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CHNG 5 CC PHNG PHP, THIT B V IU KHIN QU TRNH LN MEN

Trong t nhin xy ra mun vn cc qu trnh ln men do hot ng sng ca vi sinh vt. C th ni rng bt c mt hp cht no c trong t nhin vi sinh vt cng c th tng hp c. Do vy ln men l mun hnh mun v, nhng tt c cc qu trnh ny d l trong t nhin, trong phng th nghim hay trong sn xut cng nghip u c mt nguyn l ging nhau. Nghin cu mt qu trnh ln men thc cht l nghin cu cc c im sinh l ho sinh v hot ng sng ca mt chng vi sinh vt, cc c im nui cy ca n vi cc thng s nh thnh phn dinh dng, cc yu t nh hnh v hot ng ca ton th qu trnh ny trong sn xut cng nghip. 5.1. Cc phng php ln men Tu thuc c im sinh l ca vi sinh vt nui cy i vi oxy, ta coi qu trnh l hiu kh hay k kh khng bt buc. i vi ln men k kh thc hin theo phng php nui cy chm, ngha l vi sinh vt nui cy su tronh mi trng, thnh thong khuy tng s trao i gia t bo vi sinh vt vi mi trng trong sut qu trnh khng sc kh. Vi qu trnh ln men k kh khng bt buc, nh trong ln men ru cc ging men khi c oxy th ng sang sinh trng, tng sinh khi, khi thiu oxy th ng sang hng tch t etanol. V vy ln men ru thi k u thng c cp khng kh ging nm men pht trin tt, sau ngng sc kh ln men ru. Ln men hiu kh c thc hin nh hai phng php c bn: nui cy b mt v nui cy b su. 5.2. Ln men b su trong mi trng lng

Ln men chm l phng php c ph bin rng nht trong quy trnh ln men cng nghip, v c th kim sot c ton b cc khu trong qu trnh mt cch d dng. So vi phng php ln men b mt, th ln men chm c nhiu u im l: t chon b mt (khng mt nhiu din tch), d c gii ha v t ng ha trong qu trnh theo di. Tuy nhin phng php ln men chm i hi u t nhiu kinh ph cho trang thit b. Ngoi ra, nu mt m ln men, v mt l do no b x l th khng th x l cc b c, a phn phi hy b c qu trnh ln men, gy tn km ln. Ph liu ca qu trnh ln men thi ra phi km theo cng ngh x l chng nhim mi trng.

Phng php ny dng cho c vi sinh vt k kh v hiu kh. i vi nui vi sinh vt k kh trong qu trnh nui khng cn sc kh ch thnh thong khuy trn cn vi vi sinh

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vt hiu kh th phi sc kh lin tc. y l phng php hin i c dng trong khong na cui th k XX v cho kt qu rt to ln i vi cng ngh vi sinh.

Nui cy chm hay nui cy b su dng mi trng dch th. Chng vi sinh vt cy vo mi trng c phn tn khp mi im v chung quanh b mt t bo c tip xc vi dch dinh dng. c im ny i hi trong sut qu trnh nui cy phi khuy v cung cp xy bng cch sc kh lin tc. Ngy nay phng php nui cy chm c dng ph bin trong cng ngh vi sinh sn xut men bnh m, protein n bo, cc ch phm vi sinh lm phn bn, thuc tr su, cc enzyme, cc acid amin, vitamin, cc cht khng sinh, cc cht kch thch sinh hc v.v...

Phng php nui cy chm c mt s u im: - Tn t mt bng trong xy dng v lp t dy chuyn. - Chi ph in nng, nhn lc v cc khon ph cho mt n v sn phm thp. - D t chc c x nghip c sn lng ln. - Cc thit b ln men chm d c kh ho, t ng ho . Song phng php chm cng c mt s nhc im sau: - i hi trang b k thut cao, d b nhim trng ton b. V vy, nhng thit b ln

men chm cn phi ch to c bit cn thn, chu p lc cao, i hi kn v lm vic vi iu kin v trng tuyt i (trong nui cy b mt c th loi b phn nhim trng, cc phn khc vn cn dng c).

- Trong ln men chm cn phi khuy v sc kh lin tc v vi sinh vt ch s dng c xy ho tan trong mi trng. Kh c nn qua mt h thng lc sch tp trng, h thng ny tng i phc tp v d gy nhim cho mi trng nui cy 5.2.1. Ln men gin on Trong phng php nui khng lin tc (batch - culture) hay cn gi l nui gin on, thng thng vi sinh vt sinh trng n chng no mt thnh phn ch yu ca mi trng dinh dng b gii hn. Khi culture chuyn t pha lu tha sang pha cn bng. Sinh trng gn lin vi s thay i ko di ca iu kin nui, s gim cht dinh dng v s tng khi lng t bo. Trong qu trnh trng thi sinh l ca t bo cng thay i. Thng thng vic to thnh sn phm mong mun lin quan vi mt trng thi sinh l nht nh trong pha sinh trng. Khng th duy tr c trng thi ny trong mt thi gian di. Phng php nui gin on c s dng trc ht cho s ln men v trng,v cch nui ny l d dng v mt k thut.

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Sinh trng l biu th s tng trng cc thnh phn ca t bo. i vi cc vi sinh vt c hnh thc sinh sn bng ny chi hay phn i th sinh trng dn ti s gia tng s lng t bo. T bo tng trng n mt mc nht nh th s phn ct thnh hai t bo th h con c kch thc hu nh bng nhau. i vi cc vi sinh vt a nhn th s phn cch nhn khng ng hnh vi s phn ct t bo - s sinh trng lm tng kch thc t bo m khng lm tng s lng t bo. V vi sinh vt rt nh b cho nn l i tng rt khng thun tin nghin cu v sinh trng v pht trin. Chnh v vy m khi nghin cu v sinh trng, ngi ta thng xt n s bin i v s lng ca c qun th vi sinh vt.

NG CONG SINH TRNG

S sinh trng qun th vi sinh vt c nghin cu bng cch phn tch ng cong sinh trng trong mt mi trng nui cy vi sinh vt theo phng php nui cy theo m (batch culture) hoc trong mt h thng kn. C ngha l vi sinh vt c nui cy trong mt thit b kn, trong qu trnh nui cy khng thay i mi trng v thi gian nui cy cng ko di th nng cht dinh dng cng gim st, cc cht ph thi ca trao i cht cng tng ln. Nu ly thi gian nui cy l trc honh v ly s logarit ca s lng t bo sng lm trc tung s c th v c ng cong sinh trng ca cc vi sinh vt sinh sn bng cch phn i. ng cong ny c 4 giai on (phases) khc nhau.

Hnh 14.1: ng cong sinh trng trong h thng kn (Theo sch ca Prescott, Harley v Klein)

Giai on Tim pht (Lag phase)

Khi cy vi sinh vt vo mt mi trng mi s lng thng khng tng ln ngay, l giai on Tim pht hay pha Lag. Trong giai on ny t bo cha phn ct nhng th tch v khi lng tng ln r rt do c s tng cc thnh phn mi ca t bo. Nguyn nhn l do t bo trng thi gi, thiu ht ATP, cc cofactor cn thit v ribosome. Thnh phn mi trng mi khng ging mi trng c cho nn t bo cn mt thi gian nht nh tng hp cc enzyme mi nhm s dng c cc cht dinh dng

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mi. Cc t bo cng c th b thng tn v cn mt thi gian hi phc. Bt k v nguyn nhn g th kt qu vn l t bo phi t trang b li cc thnh phn ca mnh, ti to ADN v bt u tng khi lng. Giai on tim pht di hay ngn lin quan n bn thn tng loi vi sinh vt v tnh cht ca mi trng. Nu tnh cht ha hc ca mi trng mi sai khc nhiu vi mi trng c th giai on tim pht s ko di. Ngc li, nu cy t giai on logarit vo mt mi trng c thnh phn tng t th giai on tim pht s rt ngn li. Nu cy vi sinh vt t giai on tim pht hay t giai on t vong th giai on tim pht s ko di.

Giai on logarit (Log Phase) hay Pha Ch s (Exponential Phase)

Trong giai on ny vi sinh vt sinh trng v phn ct vi nhp ti a so vi bn tnh di truyn ca chng nu gp mi trng v iu kin nui cy thch hp. Nhp sinh trng ca chng l khng thay i trong sut giai on ny, cc t bo phn i mt cch u n. Do cc t bo sinh ra ch khc nhau rt t cho nn ng cong sinh trng l mt ng trn nhn ch khng gp khc (hnh 14.1). Qun th t bo trong giai on ny c trng thi ha hc v sinh l hc c bn l nh nhau cho nn vic nui cy giai on ny thng c s dng nghin cu sinh ha hc v sinh l hc vi sinh vt.

Sinh trng logarit l sinh trng ng u, tc l cc thnh phn t bo c tng hp vi tc tng i n nh. Nu cn bng dinh dng hay cc iu kin mi trng thay i s dn n s sinh trng khng ng u. S sinh trng khi nhp tng hp cc thnh phn ca t bo tng i bin ha s bin i theo cho n khi t ti mt s cn bng mi. Phn ng ny rt d quan st thy khi lm thc nghim chuyn t bo t mt mi trng ngho dinh dng sang mt mi trng giu hn. T bo trc ht phi to nn cc ribosome mi c th nng cao nng lc tng hp protein, sau l s tng cng tng hp protein v ADN. Cui cng tt yu dn n tc pht trin nhanh chng.

Lc chuyn qun th t bo t mt mi trng giu dinh dng ti mt mi trng ngho th cng c kt qu v s sinh trng khng ng u nh vy. Vi sinh vt trc c th thu c t mi trng nhiu thnh phn ca t bo nhng khi chuyn sang mi trng ngho chng cn c thi gian to ra cc enzyme cn thit sinh tng hp cc thnh phn khng c sn trong mi trng. Sau t bo mi c th phn ct, ADN mi c th ti to, nhng vic tng hp protein v ARN l chm cho nn t bo nh li v t chc li s trao i cht ca chng cho n khi chng c th sinh trng tip. Sau s sinh trng cn bng s c hi phc v tr v li giai on logarit.

Cc th nghim trn y cho thy s sinh trng ca vi sinh vt c kim sot mt cch chnh xc, phi hp v phn ng nhanh chng vi nhng s bin i ca mi trng.

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Khi s sinh trng ca vi sinh vt b hn ch bi nng thp ca cc cht dinh dng cn thit th sn lng t bo cui cng s tng ln cng vi s tng ln ca cc cht dinh dng b hn ch (hnh 14.2a). y chnh l c s s dng vi sinh vt trong vic nh lng vitamin v cc nhn t sinh trng khc. Tc sinh trng cng tng ln cng vi s tng nng cc cht dinh dng (hnh 14.2b). Hnh dng ca ng cong hu nh phn nh tc hp thu cht dinh dng nh s chuyn vn protein ca vi sinh vt. Lc nng cht dinh dng cao th h thng vn chuyn s bo ha v tc sinh trng khng tng ln cng vi s tng ln ca nng cht dinh dng.

Hnh 14.2: Nng cht dinh dng v sinh trng

(a )- nh hng ca s hn ch cht dinh dng i vi sn lng chung ca vi sinh vt. Lc nng cao th sn lng chung s t ti n nh.

(b)- nh hng ca s hn ch cht dinh dng ti tc sinh trng.

Giai on n nh (Stationary Phase) hay Pha Cn bng

Qua giai on Logarit s sinh trng ca qun th cui cng s dng li, ng cong sinh trng i ngang (hnh 14.1). Nng vi khun trong giai on n nh thng vo khong 109/ml. Vi cc vi sinh vt khc thng khng t c n nng ny. Vi ng vt nguyn sinh v vi to thng ch t n nng 10 6/ml. ng nhin, s lng t bo cui cng quyt nh bi nh hng chung ca iu kin dinh ng, chng loi vi sinh vt v cc nhn t khc. Trong giai on ny s lng t bo sng l khng thay i, c th do s lng t bo mi sinh ra cn bng vi s lng t bo cht i, hoc l t bo ngng phn ct m vn gi nguyn hot tnh trao i cht.

C nhiu nguyn nhn lm cho qun th vi sinh vt chuyn sang giai on n nh. Trong nguyn nhn ch yu l s hn ch ca cht dinh dng. Nu mt cht dinh dng thit yu b thiu ht nghim trng th s sinh trng s chm li. Vi sinh vt hiu kh thng b hn ch bi nng oxygen. Oxygen thng ha tan t trong nc,

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O2 trong ni b mi trng rt nhanh chng b tiu th ht, ch c cc vi sinh vt sinh trng b mt mi trng mi c nng O2 sinh trng. V vy khi nui cy vi sinh vt phi s dng ti my lc hay cc bin php thng kh khc. Qun th vi sinh vt cng c th b nh ch sinh trng khi gp s tch ly ca cc sn phm trao i cht c hi. Mt s vi sinh vt k kh (nh Streptococcus) c th ln men ng lm sn sinh mt lng ln acid lactic hay cc acid hu c khc, lm acid ha mi trng v c ch s sinh trng ca vi sinh vt. ng thi s tiu hao ht ng cng lm cho t bo i vo giai on n nh. Sau na l, mt s chng c cho thy khi s lng vi sinh vt t n mt gii hn nht nh th s sinh trng c th b nh ch. S sinh trng ca vi sinh vt chuyn sang giai on n nh c th do kt qu chung ca rt nhiu nhn t khc nhau

Nh chng ta. thy vi khun khi nui cy theo m s chuyn sang giai on n nh khi thiu thc n. Trong t nhin, do nhiu mi trng c nng ch dinh dng rt thp nn vi sinh vt thng chuyn sang giai on n nh. i vi vi khun vic chuyn sang giai on n nh c th l mt loi thch ng tt. Nhiu loi vi khun khng c s bin ha r rt v hnh thi (nh hnh thnh bo t ni sinh-endospore) nhng chng c th thu nh kch thc li, thng do cht nguyn sinh co li v nhn gi (nucleoid) m c li. Mt bin i quan trng hn l, khi thiu thc n vi khun s sinh ra mt loi protein i (starvation proteins) lm cho t bo khng nhiu hn vi cc thng tn bng nhiu con ng khc nhau. Chng lm tng cc lin kt peptidoglycan v s bn vng ca thnh t bo. Chng hn Dps (DNA-binding protein from starved cells), mt loi protein kt hp vi ADN ly t cc t bo i, c th bo v cho ADN. Phn t Chaperones cn tr s bin tnh ca protein v hi phc li c cc protein b tn thng. V nhng vic v nhiu c ch khc m cc t bo i c th kh b cht i v khng c vi tnh trng b i, vi s bin ha ca nhit , s tn thng v xy ha v s thm thu, cng nh tng sc khng vi cc ha cht c hi (nh chlorine chng hn). Nhng ci bin ny rt c hiu qu v lm cho mt s vi khun c th sng li sau vi nm b i. R rng vic hiu r nhng vn ny s c tm quan trng thc tin to ln i vi y hc v vi sinh vt hc cng nghip. Chng cn c th chng minh vi khun thng hn (Salmonella typhimurium) v nhiu vi khun gy bnh khc c th c kh nng gy bnh mnh hn khi b i.

Giai on t vong (Death Phase)

Vic tiu hao cht dinh dng v vic tch ly cc cht thi c hi s lm tn tht n mi trng sng ca vi sinh vt, lm cho s lng t bo sng gim xung. l c im ca giai on t vong. Ging nh giai on logarit, s t vong ca qun th vi sinh vt cng c tnh logarit (t l t bo cht trong mi gi l khng i). Tng s t bo sng v t bo cht khng thay i v cc t bo cht cha b phn hy. Mun xc nh s lng t bo sng phi pha long ra ri cy ln thch a v a vo iu kin thch hp xc nh s khun lc xut hin. Mc du phn ln vi sinh vt t vong theo phng thc logarit nhng sau khi s lng t bo t nhin gim xung th tc cht

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ca t bo chm li. l do mt s c th sng li nh c tnh khng c bit mnh. V iu ny v nhng nguyn nhn khc lm cho ng cong ca giai on t vong c th kh phc tp.

Tnh ton v qu trnh sinh trng

Khng t cc nh vi sinh vt hc tnh ton v tc sinh trng ca vi sinh vt trong giai on logarit. Tnh ton nhp sinh trng s lm c s cho cc nghin cu v sinh l hc, sinh thi hc vi sinh vt, v cn gii quyt mt s vn ng dng trong sn xut cng nghip.

Trong giai on logarit mi c th vi sinh vt tin hnh phn ct trong mt thi gian hng nh. S lng t bo tng theo phng thc 2n. Thi gian gia hai ln phn chia lin tip hay thi gian cn cho s tng i s t bo c gi l thi gian th h (generation time hay doubling time). V d a mt t bo vo mi trng nui cy, c 20 pht phn ct mt ln th sau 20 pht c 2 t bo, sau 40 pht c 4 t bo v tip tc nh vy (bng 14.1)

Bng 14.1: Mt v d v sinh trng theo logarit

Thi gian* S ln phn ct 2n S lng (N0 x 2n) lg10 Nt 0 0 20=1 1 0,000

20 1 21=2 2 0,301 40 2 22=4 4 0,602 60 3 23=8 8 0,903 80 4 24=16 16 1,204 100 5 25=32 32 1,505 120 6 26=64 64 1,806

*Thi gian th h l 20 pht, gi thit l nui cy t 1 t bo

S lng logarit t bo l 2n, n l s th h. C th biu th cc s liu trong bng 14.1 bng cng thc sau y:

Trong : N0 l s lng t bo ban u; Nt l s lng t bo thi gian t; n l s th h.

T cng thc trn c th bin i nh sau v s th h n c tnh bng logarit thp phn:

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Khi nui cy phn m (batch culture) tc sinh trng trong giai on logarit c th biu th bng hng s tc sinh trng bnh qun k (mean growth rate constant k). l s th h sinh ra trong n v thi gian, thng biu th bng s th h trong 1 gi:

Thi gian cn thit tng gp i tng s t bo l thi gian th h bnh qun (mean generation time) hay thi gian tn gp i bnh qun (mean doubling time) v c biu th bng g. Nu t=g th N t= 2N0. Thay vo cng thc trn ta c:

Thi gian th h bnh qun l o s ca hng s tc sinh trng bnh qun:

Thi gian th h bnh qun g c th cn c trc tip vo th bn logarit (semilogarithmic plot) v hng s tc sinh trng tnh ra (hnh 14.4). V d ,s lng vi khun ti gi th 10 l t 103 tng ln n 109 th :

(th h/h)

gi/th h hay 30 pht/th h

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Hnh 14.3: Sinh trng th h ca vi sinh vt (biu th 6 th h)

(Theo sch ca Prescott,Harley v Klein).

Hnh 14.4; Xc nh thi gian th h.

Thi gian th h c th xc nh bng ng cong sinh trng ca vi sinh vt.

Ly thi gian l trc honh v ly s lng t bo lm trc tung. Thi gian

tng gp i s lng ca qun th (thi gian th h) c th c trc tip trn

th

Thi gian th h thay i ty theo chng loi vi sinh vt, iu kin nui cy. Mt s vi khun thi gian th h khng qu 10 pht (0,17h) trong khi mt s vi sinh vt nhn thc (eucaryotic) li di ti vi ngy (Bng 14.2). Thi gian th h trong t nhin thng l di hn so vi khi nui cy.

Bng 14.2: Thi gian th h ca mt s loi vi sinh vt

Vi sinh vt Nhit (0C) Thi gian th h (gi) Vi khun v Vi khun lam

Beneckea natriegens 37 0,16

Escherichia coli 40 0,35

Bacillus subtilis 40 0,43

Staphylococcus aureus 37 0,47

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Pseudomonas aeruginossa 37 0,58

Clostridium botulinum 37 0,58

Rhodospirillum rubrum 25 4,6-5,3

Anabaena cylindrica 25 10,6

Mycobacterium tuberculosis 37 Khong 12

Treponema pallidum 37 33

To

Scenedesmus quadricauda 25 5,9

Chlorella pyrenoidosa 25 7,75

Asterionella formosa 20 9,6

Euglena gracilis 25 10,9

Ceratium tripos 20 82,8

ng vt nguyn sinh

Tetrahymena geleii 24 2,2-4,2

Leishmania donovani 26 10-12

Paramecium caudatum 26 10,4

Acanthamoeba castellanii 30 11-12

Giardia lamblia 37 18

Nm

Saccharomyces cerevisiae 30 2

Monilinia fructicola 25 30

XC NH S SINH TRNG CA VI SINH VT

C nhiu cch thng qua vic xc nh s bin i s lng v cht lng vi sinh vt hiu c s sinh trng ca vi sinh vt, bit c tc sinh trng v thi gian th h. Di y s gii thiu cc phng php thng dng nht cng cc u, khuyt im ca cc phng php ny. Khng c phng php no l tt nht, la chn phng php no cn ph thuc vo tng trng hp c th.

Xc nh s lng t bo

Phng php n gin nht xc nh s lng t bo l m trc tip di knh hin vi. Dng cc phng m m va nhanh chng, d dng, li r tin nht, li c th

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quan st thy kch c v hnh dng t bo. Thng dng phng m Petroff-Hausser m t bo ng vt nguyn sinh. Dng phng m hng cu c th m c cc t bo nhn nguyn thy cng nh t bo nhn tht. Vi t bo nhn nguyn thy cn nhum mu hoc l dng knh hin vi tng phn pha hay knh hin vi hunh quang (phase-constrast or fluoresence microscope) d quan st hn. Phng m c cu trc c mt su nht nh li c chia ra thnh cc nh (hnh 14.5). Khi m s lng ta a dch pha long vo phng m, y l knh (lamelle/ cover glass) ln trn, sau tin hnh m s lng di knh hin vi. Khuyt im ca phng php ny l khng xc nh c vi cc mu c s lng vi khun qu nh, chnh xc cng khng cao v khng phn bit c gia t bo sng v t bo cht.

Hnh 14.5: Phng m Petroff-Hauser:

(a)- Mt nhn nghing ca phng m- Phng m cha dch huyn ph vi khun l khong khng gian bn di l knh; (b)- Gia phin knh c phng m vi cc nh; (c) phng i khong x 400-500 tin hnh m s lng vi khun trong cc nh. Ly s lng bnh qun tnh ra mt vi khun trong mu vt. Trong phm vi 1mm2 c 225 nh , do s lng vi khun trn 1mm2 l (s vi khun/mm) x 25; v phng m c chiu dy l 0,02mm do nng vi khun trong phng m l: (s vi khun)/m2 x 25 (tng s nh) x 50= s vi khun/mm 3.

V 1 cm3=1 mm3 x 103cho nn gi th s lng vi khun bnh qun trong mi nh l 28 th trong 1 cm3 c nng vi khun l 28 x 25 x 50 x103= 3,5 x 107vi khun. Nhn vi pha long ban u (nu c) s bit c nng vi khun trong mu kim tra.

Vi ng vt nguyn sinh, vi to v nm men c th dng my m in t nh loi my Coulter Counter xc nh s lng. Nguyn l l hai bn mi l nh c in cc v ni in. Khi t bo trong dch huyn ph i qua l nh th c mi t bo i qua th

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in tr li tng ln (hoc tnh dn in gim xung) v sinh ra mt tn hiu in, my m s t ng ghi s. Kt qu xc nh ca loi my ny kh chnh xc, c th ng dng rng ri xc nh s lng hng cu v bch cu, nhng phng php ny khng thch hp xc nh s lng vi khun v d b can thip bi cc ht nh v cc vt cht dng si trong mu vt.

C hai phng php ni trn u khng phn bit c t bo sng v t bo cht. xc nh s lng t bo sng ngi ta thng dng phng php cy dch pha long ln b mt mi trng thch a. Sau khi nui cy mi vi khun s to thnh 1 khun lc. V d pha long 1 x 10-6 m c 150 khun lc th c ngha l mt vi khun trong mu l 1,5 x 108.

Dng dng c m khun lc cng thm thun tin. Phng php ny cho bit s lng cc t bo sng ca vi sinh vt. Phng php ny n gin, nhy cm v thch hp ng dng rng ri xc nh s lng vi sinh vt sng khi phn tch cc mu thc phm, nc, t...Tuy nhin kt qu cng chu nh hng ca mt s nhn t. Nu vi khun dnh thnh khi khng tch ri nhau ra th kt qu thu c l thp hn thc t., v mi khun lc khng pht trin t mt t bo ring r. V vy kt qu thu c t phng php ny c coi l s n v hnh thnh khun lc (CFU-colony forming unit). CFU khng hon ton ph hp vi s t bo sng trong mu vt. Trong qu trnh s dng phng php ny nn s dng pha long no cho s khun lc xut hin trn a ch nm trong phm vi khong 30-300 m thi. ng nhin mi trng dinh dng khng th p ng chung cho mi loi vi sinh vt, do kt qu thu c bao gi cng thp hn thc t. Khi trn thch vi dch pha long th thch ngui khng lm cht vi khun hay lm thng tn vi mt s loi mn cm vi nhit . Vic cy cy dch pha long trn b mt ri dn u bng que gt thy tinh thng cho kt qu cao hn v s lng vi sinh vt so vi phng php trn vi mi trng thch cha ng.

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Hnh 14.6: Tch khun lc v phng php kim tra s lng vi sinh vt thng qua m khun lc mc trn mi trng thch a.

(a) (b)- Cch ria cy tch khun lc ring r (khng dng m s lng) (c)(d)- Cch pha long ri trn vi mi trng thch cha ng

(e)(f)- Cch dn dch pha long bng que gt trn mt thch (cho s lng khun lc nhiu hn).Theo sch ca K.P.Talaro,2005.

xc nh s lng vi sinh vt cn c th nui cy giy lc lc dch pha long mu vt. Phng php ny gi l phng php mng lc (membrane filter). Dng mt thit b lc c bit t va mt giy lc hnh trn c cc l nh hn kch thc vi khun v cc vi sinh vt khc. Sau khi lc t giy lc ln mi trng thch thch hp hoc thm t mng lc bng dch mi trng thch hp ri nui cy 24 gi. m s khun lc mc trn giy lc tnh ra mt vi khun sng c mt trong mu vt (hnh 14.7)

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Hnh 14.7: Phng php lc mng xc nh s lng vi sinh vt

Phng php ny thch hp s dng phn tch vi sinh vt trong nc. C th dng cc mi trng khc nhau thch hp vi cc nhm vi sinh vt khc nhau (hnh 14.8)

Hnh 14.8: Cc loi khun lc mc trn mng lc. Theo sch ca Prescott,Harley v Klein (2005)

(a)- Tng s vi khun mc trn mi trng tiu chun, Dng ch th mu nhum khun lc cho d im;

(b)- Dng mi trng thch hp kim tra nhm vi khun coliform c ngun gc t phn (khun lc bt mu xanh);

(c)- Dng mi trng thch m-Endo xc nh vi khun E.coli v cc Coliform khc- khun lc c mu lc;

(d)- Nm si v nm men mc trn mi trng Thch - Mch nha.

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Phng php mng lc cn dng m trc tip vi khun. Dch mu vt c lc qua mt mng polycarbonate mu en. Vi khun trn mng lc c nhum mu hunh quang bng thuc nhum acridine da cam hoc DAPI (diamidino-2-phenylindole). Quan st di knh hin vi hunh quang c th thy cc t bo vi sinh vt hin ln mu da cam hay mu lc trn mt nn en. Hin c nhng kit thng mi cho php phn bit t bo sng v t bo cht khi kim tra.

Xc nh khi lng t bo

S sinh trng ca vi sinh vt khng ch biu hin s lng t bo m cn c s tng trng ca tng khi lng t bo. Phng php trc tip nht l xc nh trng lng kh ca t bo. Trc ht cn ly tm thu nhn sinh khi t bo. Sau ra t bo ri lm kh trong l sy ri cn trng lng kh. Phng php ny thch hp xc nh s sinh trng ca nm. Phng php ny tn thi gian v khng tht mn cm. i vi vi khun v trng lng tng c th l rt nh, thm ch phi ly tm ti vi trm ml mi s lng xc nh trng lng sinh khi kh.

Phng php nhanh hn, mn cm hn l dng phng php o c nh tn x nh sng. Mc tn x nh sng t l thun vi nng t bo. Lc nng vi khun t n 107 t bo/ml th dch nui cy s vn c, nng cng tng th c cng tng theo v lm cn tr nh sng i qua dch nui. C th o tn x nh sng bng quang ph k (spectrophotometer). mt mc hp th nh sng thp, gia nng t bo v gi tr hp th nh sng c quan h tuyn tnh (hnh 14.9). Ch cn nng vi sinh vt t ti nng c th o c l u c th dng phng php o c trn quang ph k xc nh s sinh trng ca vi sinh vt. Nu hm lng mt s vt cht trong mi t bo l ging nhau th tng lng cht trong t bo c tng quan trc tip vi tng sinh khi vi sinh vt. Chng hn, thu t bo trong mt th tch nht nh ca dch nui cy, ra sch i ri o tng lng protein hay tng lng nitrogen, c th thy s tng qun th vi sinh vt l ph hp vi s tng tng lng protein (hay N). Cng tng t nh vy, vic xc nh tng lng chlorophyll c th dng o sinh khi to; o hm lng ATP c th bit c sinh khi ca cc vi sinh vt sng.

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Hnh 14.9: o s lng vi sinh vt bng phng php o c.

Thng qua vic o hp th nh sng c th xc nh c sinh khi vi sinh vt. Khi s lng t bo tng ln s dn n vic tng c, mc tn x nh sng nhiu hn v quang ph k s o c mc tng ln ca tr s hp th nh sng. Trn quang ph k c hai thang chia : pha di l tr s hp th nh sng, pha trn l mc thu quang. Khi tr s hp th nh sng tng ln th mc thu quang h xung

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5.2. Ln men lin tc Cc phng php nui cy lin tc c th l: - Phng php n cp: nui vi sinh vt trong mt ni ln men, mi trng dinh

dng c b sung cng nh mi trng ln men rt ra khi ni ln men mt cch lin tc vi cng mt tc . Phng php ny n gin, d ng dng vo sn xut i vi t bo nm men thu sinh khi hoc sn phm l cc cht chuyn ho gn trc tip vi s pht trin ca t bo.

- Phng php nhiu cp: Vi sinh vt c nui h thng ni ln men t lm nhiu cp. Ni th nht c dng cho vi sinh vt pht trin tt nht, cc ni sau cc t bo tit ra cht chuyn ho. Mi trng dinh dng mi c b sung vo ni th nht v t ln lt chy vo ni tip theo.

Trong cc h thng h ca phng php nui lin tc th ni ln men thng xuyn c cung cp thm dung dch dinh dng mi, v cng vi mc nh vy, mi trng b s dng mt phn v cc t bo c rt i. Vic khuy v thng kh nhm trn u cht cha trong ni ln men (h thng ng nht). Nh vy cc t bo trong ni ln men lun lun sinh trng theo hm s m v lun lun tn ti trong cng nhng iu kin sinh l. Tuy nhin, cc t bo ang phn chia v cc t bo khng phn chia cng tn ti v khng c s sinh sn ng b.

H thng lin tc c iu khin bi cc yu t ho hc chemostas. Khi chuyn t trng thi ny sang trng thi khc th trng thi cn bng mi t c sau mt thi gian. Nh vic tng tc dng vo m sinh trng c th c tng gn tc cc i. Tc pha long (D) v tc sinh trng () l bng nhau trong phm vi ca tc pha long tiu chun.

Cc h thng lin tc c ngha cng nghip. c im ca nhng h thng ny l ch, cc t bo li trong h thng hoc a tr li , trong khi mi trng chy i khng ngng. V cc t bo ch hot ng trong mt thi gian nht nh nn sau mt thi gian no cn phi thay th hoc b sung chng. Thc cht th h thng ny l s ko di pha cn bng ca s nui gin on nh vic a c cht vo mt cch lin tc. Cc t bo, hoc c gi li trong h thng nh trng hp ca vi khun acetic sinh trng trn v bo g ca phng php ln men nhanh, hoc c tch ra v a tr li nh trong sn xut bia ru. Trong vic lm sch nc thi, cc m vi khun cng b gi li trong cc b bn sng. Mt kiu khc l cho dng dung dch dinh dng chy vo nhng vng nm. l kiu nui ni ca h thng lin tc kn. quy m phng th nghim, cc h thng c kim tra, trong t bo v c cht c tch ring bng cc mng hoc dng c lc (ni ln men - mng).

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Hin nay vic nui lin tc c ng dng nhiu trong cng nghip sn xut sinh khi v cc sn phm ln men. Vic sn xut cc cht trao i bc mt v bc hai cng nh cc enzyme thng c tin hnh theo cch khng lin tc.

u im ca phng php nui cy lin tc: - Gim bt thi gian lm v sinh thit b, kh khun v lm ngui. - Gim bt th tch ca ton b thit b. - Lao ng d dng v c kh nng t ng ho cc thao tc. - Tng hiu sut ca ton b qu trnh cng ngh nh chn lc tt nht cc iu kin

thao tc. Nhc im: - i hi cn b v cng nhn thnh tho chuyn mn. Khi hot ng, cng mt lc

phi c cc dng nng lng cn thit, gi thnh cao i vi t ng ho v dng c o lng hin i.

- Trong qu trnh nui cy t bo vi sinh vt c th c nhng t bin bt ng xy ra lm hng c qu trnh.

- Phi v khun tuyt i trong ton b thi gian thao tc. V trong qu trnh nui lin tc to ra cc iu kin ti u cho chng nui cy th cng ti u i vi nhiu loi tp khun.

- i vi cc vi sinh vt sinh h si nh nm mc v x khun rt kh tch h si mt cch v khun v c bit l hiu sut chuyn ho thng thp hn so vi nui cy tng m vi nhng chng sn ra cht chuyn ho khng gn vi s pht trin.

Hin nay vic nui lin tc c ng dng nhiu trong cng nghip sn xut sinh khi v cc sn phm ln men. Vic sn xut cc cht trao i bc mt v bc hai cng nh cc enzyme thng c tin hnh theo cch khng lin tc.

u im ca phng php nui cy lin tc: - Gim bt thi gian lm v sinh thit b, kh khun v lm ngui. - Gim bt th tch ca ton b thit b. - Lao ng d dng v c kh nng t ng ho cc thao tc. - Tng hiu sut ca ton b qu trnh cng ngh nh chn lc tt nht cc iu kin

thao tc. Nhc im:

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- i hi cn b v cng nhn thnh tho chuyn mn. Khi hot ng, cng mt lc phi c cc dng nng lng cn thit, gi thnh cao i vi t ng ho v dng c o lng hin i.

- Trong qu trnh nui cy t bo vi sinh vt c th c nhng t bin bt ng xy ra lm hng c qu trnh.

- Phi v khun tuyt i trong ton b thi gian thao tc. V trong qu trnh nui lin tc to ra cc iu kin ti u cho chng nui cy th cng ti u i vi nhiu loi tp khun.

- i vi cc vi sinh vt sinh h si nh nm mc v x khun rt kh tch h si mt cch v khun v c bit l hiu sut chuyn ho thng thp hn so vi nui cy tng m vi nhng chng sn ra cht chuyn ho khng gn vi s pht trin.

Trong cc phn trn chng ta xem xt vic nui cy phn m (batch cultures) trong cc h thng kn, tc l khng c chuyn b sung cht dinh dng, cng khng thi loi cc sn phm c hi sinh ra trong qu trinh sng. Giai on logarit ch duy tr qua vi th h sau chuyn vo giai on n nh. Nu nui cy vi sinh vt trong mt h thng h, trong qu trnh nui cy thng xuyn b sung cht dinh dng v thi loi cc cht cn b th c th lm cho mi trng lun gi trng thi n nh. l h thng nui cy lin tc (continuous culture system). Trong h thng ny s sinh trng ca vi sinh vt lun gi c trng thi logarit, nng sinh khi vi sinh vt lun gi c n nh trong mt thi gian tng i di.

Gi th ta c mt bnh nui cy trong vi khun ang sinh trng, pht trin. Ta cho chy lin tc vo bnh mt mi trng mi c thnh phn khng thay i. Th tch bnh nui cy gi n nh. Dng mi trng i vo b p cho dng mi trng i ra vi cng mt tc . Ta gi th tch ca bnh l v (lit), tc dng mi trng i vo l f (lt/ gi). Tc (hay H s) pha long c gi l D (f/v). i lng D biu th s thay i th tch sau 1 gi. Nu vi khun khng sinh trng v pht trin th chng s b rt dn ra khi bnh nui cy theo tc :

= dX/dt = D.X

X l sinh khi t bo

Ngi ta thng dng hai loi thit b n nui cy lin tc vi sinh vt. l Chemostat v Turbidostat.

Chemostat

Khi s dng Chemostat nui cy vi sinh vt ngi ta a mi trng v khun vo bnh nui cy vi lng tng ng vi tc a mi trng cha vi khun ra khi

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bnh nui cy (xem hnh 14.10). Trong mi trng mt s cht dinh dng thit yu ( nh mt vi acid amin) cn khng ch nng trong mt phm vi nht nh. V vy tc sinh trng ca vi sinh vt trong h thng quyt nh bi tc mi trng mi c a vo h thng v nng t bo ph thuc vo nng cc cht dinh dng c hn ch. Nhp i mi cht dinh dng biu th bi nhp pha long D (dilution rate). Tc lu thng ca cht dinh dng (ml/h) c biu th bng f v th tch bnh nui cy l V (ml):

D= f/V

Chng hn nu f l 30ml/h v V l 100ml th nhp pha long D l 0,30h-1. C s lng vi sinh vt v thi gian th h u c lin quan n nhp pha long (hnh 14.11). Trong mt phm vi nhp pha long tng i rng th mt vi sinh vt trong h thng l khng thay i.. Khi nhp pha long tng ln, thi gian th h h xung (tc sinh trng tng ln), khi cht dinh dng hn ch b tiu hao ht. Nu nhp pha long qu cao th vi sinh vt b loi ra khi bnh nui cy trc khi kp sinh si ny n bi v lc nhp pha long cao hn tc sinh trng ca vi sinh vt. Nng cc cht dinh dng hn ch tng ln khi nhp pha long tng cao vi c t vi sinh vt s dng chng.

Hnh 14.10: Nui cy lin tc trongChemostat v Turbidostat

Hnh14.11: H thng nui cy lin tc (Chemostat)

Khi nhp pha long rt thp th nu tng nhp pha long s lm cho c mt t bo v tc sinh trng u tng ln. l do hiu ng ca nng cht dinh dng i vi nhp sinh trng (growth rate). Quan h ny c lc c gi l quan h Monod (Monod relationship). Trong iu kin nhp pha long thp , ch c t i cht dinh dng c cung cp th t bo phi dng phn ln nng lng duy tr s sng ch khng dng sinh trng, pht trin. Lc nhp pha long tng ln, cht dinh

49

dng tng ln, t bo c nhiu nng lng c cung cp, khng nhng duy tr s sng m cn c th dng sinh trng, pht trin, lm tng cao mt t bo. Ni cch khc, khi t bo c th s dng nng lng vt qu nng lng duy tr (maintenance energy) th nhp sinh trng s bt u tng ln.

Hnh 14.12: T l pha long trong chemostat v sinh trng ca vi sinh vt

5.1.4. Thit b nui cy vi sinh vt trn mi trng lng

Nui cy vi sinh vt sn xut cc sn phm ca cc cht hot ho sinh hc l qu trnh tinh vi v phc tp nht thu nhn cc sn phm tng hp vi sinh. Tng hp sinh hc cc cht hot ho sinh hc do vi sinh vt to ra ph thuc vo mt s yu t nh nhit , pH ca mi trng v canh trng pht trin, nng ho tan, thi gian nui cy, kt cu v vt liu thit b.

Ph thuc vo cc phng php ng dng nh gi hot ng thit b ln men dng cy chm vi sinh vt v c chia ra mt s nhm theo cc du hiu sau:

Theo phng php nui cy - cc thit b hot ng lin tc v gin on. Theo tit trng - cc thit b kn v cc thit b khng i hi kn nghim

ngt. Theo kt cu - cc thit b ln men c b khuch tn v tuabin, c my thng gi

dng quay, c b o trn c hc, c vng tun hon bn ngoi; cc thit b ln men dng thp, c h thng gi kiu phun.

Theo phng php cung cp nng lng v t chc khuy trn, thng gi cc thit b cung cp nng lng cho pha kh, pha lng v pha tng hp.

Trong cng nghip vi sinh thc t hu nh tt c cc qu trnh nui cy sn xut ra

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cc cht hot ho sinh hc c tin hnh bng phng php gin on trong cc iu kin tit trng.

Cc thit b ln men nui cy vi sinh vt trong iu kin tit trng Nui cy cc vi sinh vt phn ln c tin hnh trong cc iu kin tit trng.

tit trng ca qu trnh c m bo bng phng php tit trng thit b ln men, cc ng ng dn, cm bin dng c; np mi trng dinh dng tit trng v ging cy thun chun vo thit b ln men c tit trng; khng kh tit trng thng gi canh trng v cht kh bt tit trng; cc dng c cm bin tit trng trong thit b ln mn kim tra v iu chn cc thng s ca qu trnh ; bo v m kn trc ca bc huyn o, cc ng ng cng ngh v ph tng qu trnh nui cy

4.1.4.1. Thit b ln men cbo trn c hc dng si bt Dng thit b ln men ny c s dng rng ri cho cc qu trnh tit trng

nui cy vi sinh vt - sn sinh ra cc cht hot ho sinh hc. Thit b ln men c th tch 63 m3. Dng thit b ln men ny l mt xilanh ng

c ch to bng thp X18H10T hay kim loi kp c np v y hnh nn (hnh 7). T l chiu cao v ng knh bng 2,6:1. Trn np c b dn ng cho c cu chuyn o v cho kh bt bng c hc; ng ni np mi trng dinh dng, vt liu cy, cht kh bt, np v thi khng kh; cc ca quan st; ca a vi ra; van bo him v cc khp ni cm cc dng c kim tra.

Khp x 16 y ca thit b dng tho canh trng. Bn trong c trc 6 xuyn sut. Cc c cu chuyn o c gn cht trn trc. C cu chuyn o gm c cc tuabin 8 c ng knh 600 1000 mm vi cc cnh rng 150 200 mm c nh v 2 tng, cn tuabin h th ba c gn cht trn b si bt 13 phn tn cc bt khng kh. B si bt c dng hnh thoi c lm bng nhng ng t l. phn trn ca b si bt c khong 2000 3000 l theo kiu bn c.

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Hnh 7. Thit b ln men vi b o trn c hc dng si bt c sc cha 63 m3: 1- ng c; 2- Hp gim tc; 3- Khp ni; 4- bi; 5- Vng bt kn; 6- Trc;

7- Thnh thit b ; 8- My khuy trn tuabin; 9- Btrao i nhit kiu ng xon; 10- Khp ni; 11- ng np khng kh; 12- My trn kiu cnh qut; 13- Bsi bt; 14- My khuy dng vt; 15- ; 16- Khp tho; 17- Ao; 18- Khp np liu; 19- Khp np khng kh

ng c - b truyn ng lm quay trc 6 vcc c cu o trn 8, 12, 14. S dng b gim tc v b dn ng c dng in khng i iu chnh v cp s vng quay trong gii hn 110 200 vng/ pht.

Thit b ln men c trang b o 17, gm t 6 8 . Mi c 8 rnh c ch to

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bng thp gc c kch thc 12060 mm. Din tch lm vic ca o 60 m2. B mt lm vic bn trong 45 m2 gm ng xon 9 c ng knh 600 mm vi s vt 23 khi tng chiu cao ca rut xon 2,4 m.

Thit b ln men c tnh ton hot ng di p sut d 0,25 MPa v tit trng nhit 130 1400C, cng nh hot ng di chn khng. Trong qu trnh nui cy vi sinh vt, p sut bn trong thit b 50 kPa; tiu hao khng kh tit trng n 1 m3/(m3/pht). Chiu cao ct cht lng trong thit b 5 6 m khi chiu cao ca thit b hn 8 m.

tin li cho vic thao tc v trnh nhng sai lm cn dn vo thit b s ch dn thao tc (hnh 10.2).

m bo tit trng trong sut qu trnh (gi c hi), cc trc ca c cu chuyn o phi c vng bt kn. Cc vng bt kn c tnh ton hot ng p sut 0,28 MPa v p sut d khng nh hn 2,7 kPa, nhit 30 2500C v s vng quay ca trc n 500 vng/ pht. Nh cc vng m ny m ngn nga c s r r mi trng hay s xm nhp khng kh vo khoang thit b v tr nh ra ca trc.

Vng bt kn khi tip xc vi mi trng lm vic c ch to bng thp X18H10T vX17H13M2T, cng nh bng titan BT-10. Thi gian hot ng n nh ca cc vng ny khng nh hn 2000 h khi tui th 8000 h. o hng knh cho php ca trc trong vng m kn khng ln hn 0,25 mm, o chiu trc ca trc khng ln hn 0,250.

sn xut ln cc cht hot hosinh hc bng tng hp vi sinh, vic ng dng cc thit b ln men cthtch 63 m3 lkhng kinh t.

Thit b ln men c th tch 100 m3 c sn xut c. Loi ny thuc thit b xilanh c b dn ng di cho c cu o trn. C cu o trn vi hai svng quay ca trc - 120 v180 vng/ pht. Theo du hiu v kt cu n gn ging vi thit b ln men c th tch 63 m3. Bo v vng bt kn ca trc bng ca van du, c tit trng nhit n 1400C. Ngoi ra cn c bt kn d phng m mt cch t ng khi trc ngng hot ng, nhm bo v vng bt kn chnh ca trc v cho php thay i vng bt kn chnh trong qutrnh nui cy khng ph hu tit trng ca canh trng.

Trn trc lp ba my khuy o kiu tuabin dng m vi ng knh t 820 n 1100 mm. Thit b ln men c b mt trao i nhit bn trong v bn ngoi thi nhit.

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Hnh 8. S ch dn thao tc ca thit b ln men:

1- Hi vo; 2- Khng kh tit trng vo; 3- Khng kh tit trng hay hi vo vng bt kn; 4- Thot hi hay khng kh tit trng ti bsi bt; 5- Hi hay khng kh tit trng vo thit b phn trn; 6- Thi hi hay khng kh tit trng ti bly mu thnghim; 7- Thi hi hay khng kh tit trng; 8- C cu ng nhnh cvan iu chnh bng kh ng hc; 9- Np hi hay khng kh tit trng vo thit b phn di; 10- Tho nc ngng; 11- Ap k; 12- Van; 13- ng tho; 14- Van kho; 15- Van ly mu; 16- Np hi hay khng kh tit trng khi ly mu; 17- on ng ni p k kim tra; 18, 25- Cc p k; 19- Van np vt liu cy; 20- Np canh trng; 21, 23- Np dung dch chun; 22- Thi hi hay khng kh tvng bt kn; 24- ng nhnh np dung dch chun; 26- Cung cp kh thi t thit b; 27- Cung cp nc; 28- Van rt; 29- Van rt nc t o; 30- Van np nc lnh; 31- ng nhnh np nc lnh; 32- Lc; 33- Ap k; 34- Van an ton; 35- Cm bin nhit ; 36, 37- Cc dng cthcp o nhit v pH; 38- Cm bin pH met; 39- Thit b ln men; 40- C cu lm sch khng kh

c tnh k thut ca thit b ln men c sn xut c:

Thtch, m3: hnh hc: 00 lm vic: 70

Din tch bmt, m2:

bn ngoi: 9 bn trong: 7

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Thit b ln men ca Hng Nordon (Php). Kt cu ca loi thit b ln men ny

khc vi cc loi nu ch c cu phn o nm di trc gm 6 cnh iu chnh c tit din hnh ch nht, cn c cu c hc kh bt nm pha trn gm hai cnh (tit din hnh ch nht) c cc g cng. Khi nui cy nm mc, cc cnh ca c cu chuyn o c nghing di mt gc 33 340. Hnh 10.3 m t s bt kn trc nh 6 lp m vng kht c gia cng s bdung dch 0,5 % phenol tinh th.Cc lp p cht li trong ng bc nh cc guging (vt cy). m vng kht 2 chn lp gia trc 1 v cc t l 3. Hai khp ni 8 c dn ti cc l cc. Hi np theo cc khp ni ny tit trng cc vng bt. Tit trng nhit 1350C trong 1 h. Nc ngng chy vo phn di v c thi ra qua khp ni 9. Khi kt thc qu trnh tit trng khp tho nc ngng c ng li vkhng kh tit trng qua khp 5 vo c cu bt kn. Trong thi gian ca qutrnh nui cy, p sut khng kh c gi mc 0,2 0,4 MPa.

Sau khi tit trng thit b vhp sut n p sut kh quyn th np tng khng kh tit trng to p sut 0,2 MPa, vch csau mi np nc lm lnh vo thit b. Tho cht lng canh trng ra khi thit b nhkhng kh nn c tit trng.

Hnh 10.3. Bt kn trc ca thit b ln men:

p sut lm vic, MPa:

trong thit b: 0,29 trong ng xon: 0,4

Cng sut ca b dn ng, kW: 120/180 ng knh, mm: 3600

Chiu cao thit b vb dn ng, mm: 14270

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1- Trc; 2- m vng kn; 3- Cc t l; 4- Vca bnt kn; 5- Khp ni dn khng kh tit trng; 6- ng lt p; 7- Guging; 8- Khp ni np kh; 9- Khp ni thi nc ngng

Ghi ch:(1) Cng sut in c nu trn ch trong trng hp s dng thit b ln men nui cy nm mc - cho sn phm amiloglucozidaza.

Cc thit b ln men c o trn bng kh ng hc v thng gi mi trng Cc thit b m bn trong n c trang b cc vi phun, ng khuch tn, cc b lm si bt np khng kh u thuc loi ny. Khng kh vo c s dng khuy trn canh trng, m bo nhu cu oxy cho vi sinh vt v thi cc cht chuyn ho

to thnh.

Bng 2. c im k thut ca cc thit b ln men

ca Hng Nordon c o trn c hc

S vng quay ca c cu trnvng/pht

ng knh, Chiu cao, Cng sut ng Th tch,

m3

mm mm c, kW

2 T150 dn 500 2000 3260 7,5

3 250 1100 3910 18,5

15 170 1900 6350 22,5

32 175 2400 8299 30,0

60 160 2900 10650 225,0 (1)

120 120 2800 12150 225,0

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Hnh 9. Thit b ln men dng xilanh c o trn bng kh ng hc v thi kh mi

trng: 1- Khp ni tho; 2- Thit b thi kh; 3- ng xon; 4- Ca; 5- Khp ni

np khng kh; 6- Khp thi khng kh; 7- Khp np liu; 8- Cu thang; 9- ng khuch tn; 10- Ao; 11- Thnh thit b; 12- ng qup

Thit b ln men dng xilanh. Thit b loi ny v kt cu bn ngoi tng t nh thit b ln men c khuy trn bng c hc, nhng bn trong khng c c cu khuy trn bng c hc. ng khuch tn dng xilanh 9 c ming loa y, c lp bn trong thit b. My thng gi 2 c lp theo ng tm ca thit b. Nh cc cnh hng, khng kh c p sut c a vo my thng gi theo tip tuyn n tn phu trn lm cho nh tng khng kh - cht lng chuyn ng xoy. Nh tng tun hon lin tc theo vng khp kn bn trong theo mp bin ca xilanh, vng khng gian gia tng trong v tng ngoi thit b, sau mt ln na li ln trn qua ming loa. Vic chuyn o v thi kh mnh do to ra vng tun hon bn trong. thi nhit sinh l c kt qu hn, ngoi o 10 cnhiu ngn cn b sung b mt lm lnh ca ng khuch tn 9.

Kt cu ca thit b ln men c tnh ton cho hot ng di p sut d.

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c tnh k thut ca thit b ln men c o trn bng kh ng hc.

Th tch ca thit b ln men, m3: 25,

49, 63, 200

p sut lm vic, MPa: 0,2 0,3

H s cha y: 0,5

Tc thot khng kh tthit b thng gi, m/s: 25

Tiu hao khng kh, m3 cho 1 m3 canh trng vi sinh vt: 0,5 0,2

Loi ny c th tch lm vic nh hn so vi cc thit b ln men o trn bng c

hc, c hot ng vi mi trng ln bt mnh. Chng c p dng trong nhng trng hp khi ging sinh vt khng cn phi khuy trn mnh v nht khng ln.

Cc thit b ln men dng ng. Loi thit b ny dng tng cng trao i khi, gim tiu hao n v ca khng kh nn tit trng v tng tc tng hp sinh hc cc cht hot ho.

Kt cu ca cc loi thit b ln men cho php thc hin qu trnh nui cy chm khi vn tc di ca dng mi trng bng 2 m/s v ln hn.

Thit b ln men dng ng (hnh 10) bao gm khi tr ng 7, bn trong c c cu chuyn o 8 c lp cht trn trc, ng tun hon, thit b thi kh, bung trao i nhit 5, cc on ng np mi trng dinh dng, cc on ng np khng kh, rt canh trng 13 v thi kh 16.

phn di ca ng tun hon c lp c cu chuyn i 8 dng vt. Cc cnh hng c phn b trn v di vt: cc cnh trn thng ng, cn cc cnh di nghing.

H tun hon ca thit b ln men gm my phun c ni vi phn di ca thit b, bm v cc ng ng. ng tun hon 15 c dng thit b trao i nhit dng ng c hai ng gp. Bn trong ng gp trn c hai vch c c nh v trong mt phng xuyn tm, cn bn trong ng gp di khng c vch. Ngoi ra b trao i nhit dng ng cn c cc ng trao i nhit nm gia cc ng gp thng nhau v ni nhau bi cc tng chn.

Bung trao i nhit c lp cht trong gi c hai bch v c th tho lp d

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dng sa cha. B kh bt bng phng php c hc 4 c g trn np thit b ln men 3. B dn ng cho thit b kh bt 2 v bn ca ra bng phng php c hc, u c lp trn np.

Hnh 10. Thit b ln men dng trao i khi mnh BO - 40 - 0,6: 1- ng cung cp kh thi; 2- B dn ng kn; 3- Np; 4- C cu kh bt; 5- Ming m vi bung trao i nhit; 6- Hp khng kh; 7- Khi tr ng; 8- C cu chuyn o; 9- ng np nc lnh; 10- ng c; 11- Bnh ai; 12- Truyn ng bng ai hnh thang; 13- C cu tho d; 14- ng thi nc; 15- Cc ng trao i nhit; 16- ng thi khng kh; 17- ng kh bt;18- Ca quan st

Nh truyn ng bng ai hnh thang 12, m ng c 10 lm chuyn ng vt vi s vng quay 280 350 vng/pht. m bo kn v tit trng trong qu trnh nui cy cn b tr vng bt kn trn trc ca c cu chuyn o. C cu kh bt bng c hc c lp trn trc ca b dn ng nh ng rng. Kh thot ra t cht lng c dn qua ng rng trn. C cu ny gm b a hnh nn c g. iu khin ng c ti ch v iu khin t xa ly tn hiu t bng iu khin.

kho st qu trnh nui cy vi sinh vt, trn tng thit b phn b su ca quan st 8. Thit b c thit k hot ng vi p lc n 0,3 MPa.

Cc b phn t ng dng iu chnh cc thng s c bn ca qu trnh: nhit

59

canh trng bn trong thit b - theo s bin i tiu hao nc lnh trong phng trao i nhit; lng cht lng - theo s bin i thot ra ca cht lng canh trng; nng ion hydro - theo s m v tt ca bm nh lng np kim hay axit; nng oxy ho tan trong mi trng theo s bin i tiu hao khng kh tit trng; tiu hao mi trng dinh dng - theo s bin i mi trng dinh dng vo thit b v nng sinh khi - theo s bin i tiu hao mi trng dinh dng.

Kt cu ca thit b cng c kh nng kim tra tiu hao nc lnh, mc ng ho nit, nng CO2 v O2, m khng kh, nhit v p lc trong nhng im ring bit ca thit b.

Thit b ln men ny c th hot ng gin on hay lin tc. Khi kt thc qu trnh tit trng v lm lnh ca thit b v ca cc c cu ph, th rt y mi trng dinh dng tit trng v tin hnh cho hot ng c cu chuyn o thc hin tun hon mi trng theo vng khp kn. Np khng kh nn mt cch lin tc qua thit b thi kh vo khng gian gia tng v ng tun hon. Khng kh cun ht cht lng thnh dng, p v ra thnh bt nh v c khuy trn mnh vi mi trng, to ra hn hp ng ho gi.Chuyn ng quay ca mi trng c to nn trong ng tun hon nh cc cnh hng, kt qu to ra vng xoy trung tm c hm lng kh cao.

Nh ma st cht lng vi phn g ca cc ng trong b trao i nhit m s chy ri ca cc lp bin c duy tr. Khng kh thi c tch ra khi cht lng v c thi ra qua ng lt rng ca thit b kh bt.

tng cng qu trnh cn np mi trng dinh dng vo thit b qua my phun. Bm ht cht lng canh trng v y qua vi phun ca my phun, cho nn mc phn tn ca cht dinh dng t c rt cao v to ra b mt tip xc ca cc pha rt ln. S tun hon nhiu ln ca canh trng trong vng khp kn vi cc bmt nh hnh tt, bo m hiu sut cao ca qu trnh v bo m tnh ng nht ca hn hp trong khng gian vng tun hon. Bung trao i nhit bo m tt tc chy ca tc nhn lnh cao lm cho h s trao i nhit ln. B trao i nhit kiu chm ng trong ng gp cho php tng b mt n v lm lnh khong 10 ln ln hn khi truyn nng lng qua tng thit b. H s truyn nhit c tng ln mt s ln v t gn 3900 W/(m2 K).

c tnh kthut ca thit b ln men dng ng:

H s cha y: 0,6 0,7

Th tch, m3: 40

Lng mi trng c np, m3: n 28

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Ap sut, MPa:

trong tng: 0,6

trong phng trao i nhit v trong o ngoi: 0,3

trong thit b: 0,1 0,6

Cng sut b dn ng, kW:

cho c cu khuy trn: 125

cho c cu kh bt: 40

S vng quay ca trc, vng/pht:

cho c cu khuy trn: 350 v200

cho c cu khbt: 1500

Kch thc c bn, mm: 4600260012000

Cc thit b ln men khng i hi tit trng cc qu trnh nui cy vi sinh vt

Cc qu trnh nui cy sn sinh ra cc nm men gia sc thuc cc qu trnh nui cy vi sinh vt khng tit trng. Theo kt cu cc thit b ln men, sn xut nm men tng t nh cc thit b sn xut enzim, cc khng sinh chn nui, cc amino axit v cc sn phm tng hp khc, nhng khng c s bo v hi v khng kh ca trc quay v mt s b phn kt cu. Trong nhiu trng hp sn xut nm men gia sc, ng dng cc thit b c s dng trong cc qu trnh tit trng.

Cc thit b ln men c o trn bng kh ng hc v ng vin tun hon bn trong

Cc thit b nui cy nm men dng phng php bm dng bng kh nn ca h thng Lephrancia c ng vin tun hon bn trong c ng dng ph bin nht. Trong sn xut nm men thy phn thng ng dng cc thit b loi ny c sc cha 250, 320, 600 v 1300 m3. Kt cu cc thit b ln men khng c cc thit b c hc kh bt. Bt c kh di trng lc ca ct cht lng khi tun hon.

Khng kh vo thit b theo ng trung tm vo chu, ti y hn hp kh - cht lng c to thnh t nc hoa qu np vo v t cht lng phn di thit b. Hn hp trn c chuyn ng theo ng khuch tn bn trong. Mt phn khng kh c tch ra khi bt v thi ra kh quyn qua l np thit b, cn mt phn khc cng vi bt h

61

xung theo ng rnh vng gia ng khuch tn v tng. Khi chuyn ng xung di bt b kh. bi tun hon t cao 1,5 2 th tch cht lng hot ng trong mt pht. Cc thit b cng nghip c chiu cao 12 15 m. Bt dng cao ln 10 12 m. Tin hnh lm ngui thit b ln men bng ti nc tng ngoi v np nc vo o ca ng khuch tn. Tiu hao khng kh cho 1 kg nm men kh l 20 m3.

c tnh k thut ca cc thit b ln men cng nghip hot ng p sut kh quyn c gii thiu bng 10.2.

Bng 3. c tnh k thut ca cc thit b ln men c o trn bng kh ng hc v khi kh sn xut nm men gia sc

Th tch ca thit b, m3

Cc ch s

320 500 600 1300

Nng sut theo lng nc

20 30 30 35 55 62

hoa qu chy, m3/h

pH 4,5 pH 3,54,5 pH 4,24,5

Mi trng

n 5000 9000 1400016000 18000

Tiu hao khng kh, m3/h

p sut d ca khng kh,

0,6 0,75 0,4 0,6

kg lc / cm2

B mt lm lnh ca o

ng khuch tn, m2

30 503=1

50 58 504=200

Kch thc c bn, mm

570013350 760011200740014175 1100014500

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Thit b ln men hnh tr c b phn bm dng bng kh nn vi sc cha 1300 m3 Thit b loi ny c dng nui cy nm men mt cch lin tc trong nc qu.N gm c v thp hn, y hnh nn ct v np hnh nn c l chnh gia (hnh 11).

Hnh 11. Thit b ln men hnh tr c b phn bm dng bng kh nn vi sc cha

1300 m3

Bn ng khuch tn 7 c lp bn trong thit b to ra bn dng tun hon c lp. Khng kh nn c y qua ng gp 2 vo cc ng trung tm ca mi ng khuch tn, cui ng trung tm c cn v chu 8.

Thng phn phi c t trn np thit b, dch ln men, nc qu, nm men v nc amoniac cho vo cc ng khp ni 3, 4, 5. Tt c cc cu t c trn li v to ra mt dung dch dinh dng v theo cc ng ng c ng knh 100 mm chy xung di cc chu ca thit b thi kh.

Hn hp dinh dng khi chy trn qua mp chu c khuy trn vi khng kh thot qua khe di chu. Nh tng khng kh - cht lng c to thnh dng ln theo ng khuch tn n tm chn 6 th b ph v v chy xung di. Dng thit b ti dng ng gp lm lnh tng ngoi thit b.

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Thit b ln men dng thp Cc thit b ln men ny bao gm loi a v loi khng c cc c cu chuyn o

nm ngang. S khc bit ca loi thit b ny so vi cc loi thit b c nu cc phn trn l tr s t s gia chiu cao v ng knh rt ln. Thit b dng thp c nhiu trin vng bi kt cu n gin, kh nng tng cng qu trnh sinh tng hp v cng sut n v ln. u im v kt cu ca thit b dng thp l khng c cc phn quay chuyn ng v din tch chim ch nh.

Thit b ln men dng phun. Thit b ln men ca c vi s trao i khi mnh. C th tch n 10003, s dng phng php cc tia ngm.

Hot ng ca thit b (hnh 10.7) c m t di y: bm ly tm c chc nng kh kh, y cht lng n ca vo ca thit b ln men dng ng. Cht lng chy xung dc theo tng ng dng dng vng khuyn. Dng chy ri u cui nm ngang mc b mt cht lng ca hn hp b tht li trong tit din ngang ca ng v t chy thnh dng tia to ra vng p sut thp.

Khi to hn hp ng ho vi cht lng th khng kh c ht qua l nh khoang trong vng p sut thp. Cht lng si bt ( dng tia xm nhp t do, do d tr nng lng ng hc) n y ca thit b ln men, to ra trng ri mnh trong dung dch canh trng. Cc bt kh t y thit b ni ln bmt, mt ln na qua trng ri c to ra t cc tia xm nhp t do.

Nh h thi kh tng t nh th c th m bo cung cp oxy cho cc thit b ln men loi ln c th tch n 2000 m3, khi cng khuy mnh.

c tnh k thut ca thit b ln men dng phun nui cy nm mc c gii thiu bng 5.

Khi tc chuyn ng ca cc dng tia 8 12 m/s v p sut khng i th s phn tn ca khng kh s t c tt. Nh tc ng phun vng vo ca dng, nh chuyn ng im tng ca thit b v nh o trn cc bt kh m thc hin vic la chn thch hp cho xung lng ca dng np t do, nhm bo m s khuy trn mnh canh trng nui cy. Cc bt khng kh trong lung hu nh hon ton n y thit b, cn khi ni ln bmt thit b chng b ph hu bi trng ri Trong trng hp gim lng cht lng tun hon th s phn tn khng kh c tng ln ng k v n c phn b u theo ton th tch thit b. Tc trao i kh tng tuyn tnh vi s tng dng cht lng tun hon v tiu hao nng lng trong mt khong hot ng rng. Cho nn qu trnh thi kh c th iu chnh bi tc truyn kh. Trong cc thit b c kt cu c nu trn, nhu cu v nng lng np khng kh rt nh v nng lng ca dng tun hon s bo m ri cn thit trao i khi. Nhng iu kin cn

64

thit trao i khi mnh trong thit b l: ri cao, s phn tn khng kh tt, thi gian c mt ca khng kh trong canh trng lu v ng ho mi trng cao.

B Hnh 12. Thit b ln men dng phun: 1- Ca khng kh vo; 2- ng ng khng kh thi; 3- Hm tho nc; 4-

Tng thit b; 5- ng ng cp; 6- ng ng ht; 7- Bm tun hon

65

Bng 5. c tnh kthut ca cc thit b ln men dng phun sn xut c

Th tch ca thit b ln men, m3

Cc ch s

200 400 1000

Nng sut ca thit b ln men (tnh theocht kh tuyt i), kg/h 250 370

180 350

Th tch cht lng si bt, m3

80 130 400

Dung lng ca thit b, tn

2500 4400

Nng sut ca cc bm tun hon, tn/h

30 26 30 110

Bi s tun hon ca cc bm, th tch trong 1 h

S lng bm

1 2 10

125 135 210

220 2200 Tiu th nng lng in cho cc bm thi kh v ng ho, kW.h

Tiu hao khng kh trong khoang si bt cp sut gim, Nm3/h 3600 5000 60000

Kch thc,mm

ng knh 6000 8000 11500

1050

chiu cao phn tr 7500 8000

66

Bm tun hon l b phn chnh ca ton h. Phng php lung ngm c hiu qu c bit i vi cc qu trnh c tc trao i khi cao. Trong trng hp t hp tng ca cc thit b hay khi phn chia bn trong thit b c sc cha ln ra thnh 2 3 phn v tt c cc ngn c ni li nh cc mng rt mi trng theo chy t trn xung mng di, mi ln chy nh th c bo ho oxy ca khng kh.

Lng cht tun hon c hn ch bi s cp liu ca bm chuyn. Khi phn b thnh ba tng lng bm cn thit cho thit b mt tng vi chiu cao chuyn l bi s 3 th rt ngn c 3 ln. Bt c to thnh trong qu trnh thi kh cng c chuyn xung di, cho nn c cu kh bt c nh v phn di ca thit b. Tin hnh thi nhit sinh l trong b trao i nhit c bit.

ng dng dng thit b trn nui cy vi sinh vt trong iu kin tit trng rt phc tp v do kh khn v kn ca cc bm tun hon, nhng tin li i vi qu trnh tit trng bng hi. Nhng c nhng u im: c cu n gin, dung lng ln, bo m thi kh mnh v m bo truyn khi m khng cn c cu o trn, lm cho kt cu ny tr nn c trin vng trong cng nghip vi sinh.

Cc thit b ln men c h thng gi dng phun Loi thit b ny c ng dng nui cy chng nm men c bit trn mi

trng dinh dng cha parafin lng. Thit b ln men -50. Kt cu ca thit b c dng dung lng xilanh ng vi sc

cha 800 m3 (h s cha y 0,4), c chia thnh 12 ngn (hnh 10.8). Mi ngn c c cu khuy trn v thi kh. Thit b c trang b cc b o trn thc hin chc nng khuy trn pha lng v cung cp khng kh. Trong qu trnh quay ca b o trn v tr thot cht lng, khng kh c ht vo, vng h p c to ra. Khi khng kh ho mnh vo cht lng, lm bo ho oxy trong cht lng.

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Hnh 13. Thit b ln men -50: 1- Rnh vng; 2- ng thng gi; 3- B kh bt; 4- Bphn ly; 5- Xilanh; 6- Dn

ng; 7- B trao i nhit; 8- ng khuch tn; 9- Cc xilanh; 10- C cu phun

c tnh kthut ca thit b ln men -50:

Nng sut ca thit b tnh theo sinh khi kh tuyt i,tn/ngy 27,0

Nng sut thit b khi g t trung tm 13 ngn,tn/ngy: 30

Dng cht lng, m3/h: 37,5

Dung tch, m3:

khi cha hot ng: 800

khi hot ng: 320

Nhit hot ng, 0C: 32 34

Din tch bmt trao i nhit, m2: 2700 3000

Tiu hao khng kh, m3/h: 36160

Slng c cu thng gi: 12

Cng sut ng c, kW: 3,5

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Thit b nui cy nm men trn mi trng rn -76-900 nui nm men parafin. Hin ti loi kt cu ny c thc nghim rng ri trong cc nh my sn xut cht c cha vitamin v protein. Thit b ln men (hnh 10.9) gm v 1; vng tun hon t l 2; ng khuch tn trung tm 5; cc c cu thi kh 3 c lp trong vng tun hon t l v trong ng khuch tn trung tm; cc b trao i nhit 7 v b tch git 4. ng c 6 dn ng cho cc c cu thi kh. Np vo thit b mi trng dinh dng cha parafin, mui khong, cc nguyn t vi lng, nc amoniac, v tho thnh phm ra khi b phn ly qua khp ni. Np khng kh thi cho canh trng bng phng php t ht. Khi cc b thng gi sc kh cho mi trng th s trao i khi c xy ra qua b trao i nhit to ra nhng dng ln xung.

V thit b c ch to bng thp khng g, hai lp, cn cc b trao i nhit, cc c cu trao i kh vcc vch ngn - bng thp nguyn khi.

Hnh 14. Thit b nui cy nm men trn mi trng rn -76-900

c tnh k thut ca thit b ln men -76-900

Nng sut thit b, tn/ngy: 30 36

Dung lng, m3:

khi cha hot ng: 900

69

khi hot ng: 450

p sut, MPa: 0,02

Nhit hot ng, 0C: 32 34

Mi trng, pH: 4,2 4,4

Din tch b mt trao i nhit, m2: 2700

Tiu hao khng kh ( iu kin bnh thng), m3/h: 54000

S lng cc c cu thi kh: 13

Cng sut ng c in, kW: 315

Kch thc c bn, mm: 17000170006500

Khi lng, tn: 535

Nhc im ca thit b ln men c h phun ch: trc thit b b rung ng; nhim bn b mt trao i nhit v gim h s trao i nhit.

Thit b ln men trao i khi mnh Mc ch chnh ca loi thit b ny l tng nng vi sinh vt trong dung dch

canh trng, tng iu kin thi kh v tng nng sut thit b. Thit b (hnh 15) l mt dung lng xilanh 17, bn trong lp xilanh hng 2. Hai

on ng 4 v18 nh v cho xilanh hng trong dung lng. on ng 18 c lp cht n y v chia dung lng ra lm hai phng: phng 19 dng nui cy canh trng, cn trong phng 20 tn dng b sung nguyn liu ban u. on ng 4 lp cch mt y ca dung lng. Bn trong xilanh hng 2 v trong khng gian gia tng dung lng v on ng 4 c b tr cc ng gp 16. Cc ng gp c lp cht bi cc ng t l 21. Trong khng gian gia xilanh hng 2 v cc on ng 18 v4 c cc b trao i nhit 1. np khng kh n cc ng gp trong phng 19 dng ng gp phn phi 7, cn trong phng 20 - ng gp 5. phn trn ca dung lng c ng gp 14 thu nhn v lm kh bt, bn trong c lp cc a hnh nn 15. Khng kh thot ra t phng 19 qua b tch kh 9. My kh bt bng c hc 12 vi b dn hng c lp t trn cc a 15. Mi trng dinh dng c y vo thit b qua khp 6. Sinh khi c tho ra khi thit b qua khp 11, cn khng kh - qua khp ni 8 v13.

Thit b hot ng nh sau: np hn hp dinh dng ban u vo phng 19 qua khp ni 3, cn khng kh - vo thit b qua khp ni 6. Trong phng 19 xy ra nui cy sinh khi. Tun hon v o trn cht lng c thc hin bi thit b bm dng bng

70

kh nn. T phng nui cy, cht lng canh trng chy qua on ng 12 vo phng 20, ti y xy ra tn dng b sung nguyn liu. Bn trong phng 19 v 20 dung dch canh trng c thi kh nh cc ng c t nhiu l. Sinh khi tho ra khi phng cng vi pha bt c to thnh phn trn ca phng. Sau bt ni ln theo cc ng rnh gia cc a nn 15, c tch khi cht lng v c c li. Kh bt c c bng b kh bt c hc 12 v tho ra qua khp ni 11. Thi khng kh khi phng 19 qua khp ni 8 nh b tch kh 9, cn khi phng 20 - qua khp ni 13.

Hnh 15. Thit b cy ln men trao i khi mnh Kt cu ca cc c cu thi kh trong my phun kin tuabin My phun kiu tuabin l loi kt cu ht hai tng c cc ca trn v di

np v thi dung dch. Loi ny hot ng nh sau: khng kh vo c trn vi cht lng, khi thot ra th khng kh c hng ln trn v sau khi qua b trao i nhit c chia ra lm hai dng. Khi i qua phn trung tm ca c cu tun hon, dng th nht vo ca trn ca c cu phun, cn dng th hai hng xung di theo ng vin ca c cu tun hon v khi chuyn ng di y gi th vo ca di.

71

My phun kiu tuabin c cc vng t l Loi kt cu ny c dng thi kh v khuy trn mi trng ging khi nui

cy vi sinh vt, c bit l nm men. Nhm mc ch n gin ho kt cu ca my phun kiu tuabin, c cu ph dng cht lng c dng vng t l, c lp gia cc cnh ca qut v cc phn to ng vin ca v my.

My phun (hnh 10.11) gm v10 c lp cht trong ng thng rng kh 1 vi

cc phn to ng vin 6 hnh thnh vi phun 4; cc rnh phn b11 bn trong vi phun hn hp kh - cht lng; qut c lp trong v gm cc a 9 v 8, cc rnh 3 gia cc a, c cu cho dng cht lng c dng vng t l 5 c lp cht gia cc cnh qut v cc phn l ca rto. Cc cnh ca my bm dc trc y cht lng canh trng v dn vo phn chy 7 ca my phun, ti y cc vng t l 5 s to ra nhiu vng nh. Cc dng ny s phun vo khng kh c y t qut v trong vi phun 4 s to ra hn hp hi - cht lng, nh cc cnh khuy 11 hn hp b phn tn trong cht lng. Dng kh - cht lng c phn tn chy ra ngoi. Loi ny cho php lm n gin ho kt cu ca my phun, lm tt hn s phn tn khng kh v tng tc ht oxy trong cht lng.

Hnh 16. My phun dng tuabin c cc vng t l

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My phun kiu tuabin c cc vi My phun ny c c trng bi qu trnh trao i khi tt hn, bng cch nng

cao mc phn tn kh trong cht lng v tng lng kh xm nhp vo cht lng. thc hin c iu ngi ta lp cc vi trong my theo ng knh ngoi ca cc a qut nhm ph hu dng cht lng. Khi nhng on vo ca cc cnh phun hn hp kh - cht lng c phn b gia cc vi. My phun kiu tuabin hnh 10.12 gm co v 8 vi cc on ng ng vin 2 hnh thnh vng, vi phun 4 c lp cht trn trc rng ca ng thng kh th 1; cc cnh phn b 10 bn trong vi phun phun hn hp kh - cht lng v qut gn trong v gm hai a 5, 6 vi cc cnh 3 gia cc a. Theo ng knh ngoi ca cc a ngi ta phn b cc vi 9 ph hu cc dng cht lng. Nhng on vo ca cc nhnh 10 phun hn hp kh - cht lng c phn b gia cc vi. Cht lng ban u c hng ti cc vi 9 nh cc cnh 7, ti y cht lng c phn chia ra mt s dng, chng tip xc vi khng kh vo t qut v y vo vi phun 4, ri tip tc phn tn kh trong cht lng nh cc cnh 10, 9. Sau cht lng bo ho khng kh c thot ra ngoi.

Hnh 17. My phun dng turbin c cc vi

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5.2. Ln men b mt trn mi trng rn Trong phng php nui b mt hay nui ni cc c th tn ti b mt mi

trng, do m cc t bo hng v khong khng kh c cung cp y xy. cc vng nm, cht dinh dng ca mi trng ch c hp thu nh cc t bo chm v c chuyn vo si nm kh sinh. S to vng trong phng php nui b mt dn ti mt trng thi sinh l c ngha quan trng i vi vic sn xut cc cht trao i nht nh ca nm, v d nh sn xut acid citric hay cc enzyme. Tuy nhin ngi ta vn c gng t n trng thi sinh l tng ng vi nui cy chm.

Phng php nui cy ny thng thch hp cho mt s nm mc v x khun. Vic nui thng c tin hnh trn cc khay phng xp chng ln nhau v trong cc bung cha v trng ng kn, ging c cy vo bng cch thi bo t vo bn trong bung cha. Mt hnh thc khc l nui h si nm trn cc c cht rn nh la m, cm hoc la nc trong cc thng quay chm. Phng php ny c dng sn xut mt s enzyme.

Theo phng php ny, ging vi sinh vt hiu kh sau khi cy s pht trin trn b mt v dn dn lan xung pha di theo cc k h gia cc cu t thnh phn mi trng. Vi sinh vt s dng xy ca khng kh h hp ng thi thi CO2 ra mi trng xung quanh v to nhit. Phng php ny thng thch hp cho cc qu trnh nui cy nm mc, mt s x khun v vi khun cng c th sn xut theo phng php ny.

Nui cy vi sinh vt trn b mt mi trng rn hoc bn rn c c cht dinh dng l cm c trn cc loi bt ng cc, u tng v mt s thnh phn dinh dng khc. Ngun carbon cho mi trng dinh dng l cc loi ht nh ng, go, m, i mch, u tng... c nghin v thnh mnh kch thc khong 1 - 3 mm. m ca mi trng khong 55 - 60%. Khi vi sinh vt pht trin s thi CO2 gy hin tng to nhit lm nng v kh mi trng. Cn phi thng gi, phun m hoc lm m trc tip gi cho m tng i ca khng kh khong 90%.

Nhc im ca phng php: - Tn nhiu din tch mt bng, kh c kh ho v t ng ho. - Chi ph nhn cng, in nc... cho mt n v sn phm cao.

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5.2.1. K thut chun b mi trng rn Theo phng php ny ging vsv hiu kh sau khi gieo cy s pht trin trn b mt v dnc dn lan xung pha di theo cc k h gia cc cu t thnh phn mi trng. Mi trng nui cy b mt l mi trng rn xp. Vi sinh vt pht trin s dng xy ca khng kh h hp lm tc nhn xy ha trong cc qu trnh bin i sinh ha, ng thi thi CO2 ra mi trng xung quanh v ta nhit. Mi trng dinh dng sau khi thanh trng c ti trn khay sch vi chiu dy t 3 5 cm v nui nhit thch hp trong bung nui cy c m khng kh l 90%. Ngun cacbon cho mi trng dinh dng y l cc loi ht nh ng go m, i mch, u tng ..c nghin v thnh mnh c kch thc 1 3 mm, cng vi cm go, cm m (hai loi cm ny ng vai tr l ngun cacbon v ngun cc cht sinh trng) v tru. Cm tru trong mi trng cn c tc dng lm xp tng hiu khi cho vi sinh vt nui. Chun b mi trng bng cc trn cc thnh phn u vi nc sao cho m khong 55 60% v c hp thanh trng.

Cy ging vi sinh vt t dch nhn ging hoc rc cc bo t vo khi mi trng thanh trng v ngui, thnh ng vi gi, sau ti ra khay vi chiu dy 2 5 cm (cng mng hiu kh cng tt). Khi vi sinh vt pht trin s thi CO2 to nhit ra xung quanh lm nng v kh mi trng, h si lm cho mi trng kt thnh tng. Khi cn phi thng gi, phun m hoc lm m trc tip, lt khi mi trng nui cy hoc b nh. Bung nui cy c cc gi k khay, c b phn gia nhit v lm mt, b phn phun m bng nc gi m tng i ca khng kh l 90% trnh lm kh mi trng. Nui cy b mt

Phng php b mt thng thch hp cho cc qu trnh nui nm mc, mt s trng hp l x khun nhng nhm vi sinh vt sinh trng thnh h si. Cng c mt vi trng hp nui cy vi khun theo phng php ny.

Nui vi sinh vt trn b mt mi trng rn hoc bn rn, c cht l cc loi bt ng cc, u tng v mt s thnh phn dinh dng khc. Ngy nay phng php b mt s dng cng ngh hin i hn v c trang b cc thit b o lng c th iu khin c qu trnh cho hiu sut ln men cao. Song phng php nui cy b mt vn c nhiu nhc im:

- Tn nhiu din tch mt bng

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- Kh c kh ho v c bit l rt kh t ng ho c ton b qu trnh.

- Chi ph nhn cng, in nc cho mt n v sn phm cao.

Hnh IV.1: Bung nui cy b mt

1.Gi khay 2.Van hi nng iu ho nhit

3.H thng phun nc thnh bi 4.Qut

5.Lc kh 6.ng thng kh vo 7.ng thng kh ra

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Hnh IV.2: S nui cy vi sinh vt theo phng php b mt trn khay

A. Cng on chun b lm mi trng

B. Chun b nc sch lm m mi trng C. Lm sch kh cp cho phng nui cy

D1.Khu vc ra v lm sch gi st D2. Khu vc kh trng v ra khay

E. Gi vi khay c mi trng nui cy

Ngun cacbon cho mi trng dinh dng y l cc loi ht nh ng, go, m, bobo, i mch, u tng c nghin v thnh mnh c kch thc khong 1 -3mm, cng vi cm go, cm m v tru. Cm tru trong mi trng c tc dng lm xp tng hiu kh cho vi sinh vt nui.

Cy ging vi sinh vt t dch nhn ging hoc rc cc bo t vo khi mi trng thanh trng v ngui, thnh ng vi gi, sau ti ra khay vi chiu dy khong 2 5cm. Khi vi sinh pht trin s thi CO2, to nhit ra xung quanh lm nng v kh mi trng, h si lm cho mi trng kt thnh tn. Khi cn phi

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thng gi, phun m hoc lm m trc tip, lt khi mi trng nui cy hoc b nh. Bung nui cy gi m tng i ca khng kh l 90% trnh lm kh mi trng.

Nui cy b mt vi mi trng rn v xp ngy nay c ci tin nhiu trong qu trnh: thay khay v bung nui cy bng thng quay c trc cho hoc thng b c thi kh lin tc v iu khin nhit , m. Nhng ci tin ny lm tng nng sut ca qu trnh rt nhiu.

5.2.2.Thit b nui cy vi sinh vt trn mi trng rn Nui cy vi sinh vt trn cc mi trng ti th ht c nhiu u vic hn so vi nui

cy trn cc mi trng dinh dng lng. Nh tc tng hp ca cc enzim cao hn 5 6 ln, ngoi ra canh trng nhn c c m 40 50% (trong canh trng lng 80 95%), cho php tit kim ng k ngun nng lng sy. Tuy nhin n nay phng php nui cy vi sinh vt trn cc mi trng dinh dng rn cha c ng dng rng ri trong cng nghip do cha c nhng thit b tit trng c c kh ho ng tin cy. Hiu sut v hot ho ca cc cht hot ho sinh hc, thi gian qu trnh nui cy ch yu ph thuc vo nhng yu t sau: loi vi sinh vt, thnh phn cu t ca mi trng dinh dng, lng v cht lng ca nguyn liu cy, nhit nui cy, mc thi kh ca canh trng pht trin, cng o trn, trao i khi v trao i nhit. Vic la chn dng thit b v nhng b ph tr m bo tt c nhng i hi ca cng ngh c ngha quan trng nht.

Phn loi thit b nui cy vi sinh vt trn mi trng dinh dng rn nui cy vi sinh vt trn mi trng dinh dng rn, ngi ta s dng cc loi

thit b c kt cu sau y: thit b nui cy vi sinh vt trn mi trng rn dng phng c cc khay t l nm ngang vi kch thc 400800 mm, thit b c c kh ho c khay ng t l, thit b c c kh ho dng 42, cc thit b bng ai tc ng chu k v lin tc, t my nhiu phin tc ng lin tc vi s ng dng cc my rung cng nh cc thit b dng trng quay. Nhc im ca cc thit b nui cy vi sinh vt trn mi trng rn dng phng c cc khay nm ngang t l l khi lng lao ng cho cc cng on qu ln, mc c kh ho cho cc cng on cng ngh thp v khng trnh khi s tip xc ca cng nhn vi canh trng ca vi sinh vt. T cc kt cu k trn, trong cng nghip thng ngi ta ng dng cc thit b c c kh ho c cc chu c phn b ng, cng nh cc thit b dng trng quay v hnh thp. Cc thit b dng trng quay v hnh thp c trin vng tt sn xut ln.

S tch lu mt lng ln cc ph thi nng nghip nh rm, v bng, v ht

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hng dng, ci ng, cc ph liu khi gia cng khoai ty, c ci ng, cy ma... cho kh nng s dng chng thu nhn protein chn nui, l ngun rt in cho sn xut xenluloza v tinh bt.

Tuy nhin nui cy vi sinh vt vi mc ch tng hp sinh hc protein khng th s dng cc phng nui cy bnh thng, cc phng ny c sdng nui cy nm mc trn mi trng dinh dng rn c chiu cao ca lp mi trng khng ln hn 3 5 cm. Cc x nghip sn xut cht c c cha protein v enzim thuc dng sn xut ln, cho nn i vi nhng nh my nng sut100 nghn tn trong mt nm i hi 210 nghn chu. mc nh th cn phi s dng cc thit b tho mn cc yu cu sau: chiu cao ca lp mi trng dinh dng khng nh hn 50 cm; kh nng to ra cc iu kin tit trng; s bin i sinh hc ca cc cht dinh dng trong nguyn liu thnh protein l cc i. Cc thit b sn xut cc sn phm trn c th gin on hay lin tc. Cc thit b tc ng gin on thng dng hnh trng nm ngang, loi tr qu trnh nui cy vi sinh vt c th thc hin trch ly cc cht hot ho sinh hc t canh trng nui cy.

Cc thit b nui cy vi sinh vt trn mi trng rn c cc khay t l nm ngang

Trong cc iu kin sn xut nui cy cc ging nm mc trn b mt trong cc khay, ngi ta s dng cc phng tit trng, s lng cc phng ph thuc vo nng sut tnh theo canh trng nm mc kh hng ngy. nh hng thng khi nng sut 1 tn/ngy cn 3 4 phng tit trng. i vi nh my c nng sut 10 tn/ngy s phng l 30 40. Phng tit trng l bung kn c kch thc 1000028002100 mm vi hai ca, mt ca ni vi hnh lang thi liu. Bn trong phng c ba on ng thng kh np khng kh iu ho t mt hng, cn t hng ngc li- cc ng thi khng kh trong phng. Din tch ca phng c tnh cho 18 20 gin c khong 9 10 khay cho mi bn, quy i ra cm kh l100 kg. Khong cch gia cc gin 80 100 mm, gia cc gin c khong cch rng 1000 1200 mm i li v cch tng 200 300 mm.

Cc b iu ho c lp c phn b trn cc phng tit trng nhm y khng kh c nhit 22 320C, m tng i 96 98% vo phng. Khng kh tun hon c b sung 10% khng kh sch t b iu ho chnh, cc hnh lang np v tho ca cc phng cn phi cch ly cc phng bn cnh. iu thc hin c nh thng gi hai chiu khi trao i khng kh nhiu ln (n 8 ln) v nhl m sch khng kh thi khi cc bo t.

Vic nui cy ging trong cc phng tit trng c s dng trong cc giai

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on u ca s pht trin sn xut ra cc ch phm enzim. Nhng tng to ra cc thit b dng c kh ho c cc khay nm ngang khng mang li kt qu tt v tn nhiu kim loi v nng sut thp.

Thit b c cc khay c phn b ng Thit b nui cy vi sinh vt trn mi trng dinh dng rn kolovieva. Phng ca

thit b ny lb cha hnh hp bng kim loi c c nh trn cc tr nh h ging n hi. Np lt c ng kn trn thit b, cn di y lt. Bn trong phng c khong 50 mm b tr hp ng tng kp t l, khng kh c y qua cc hp ny. Cc hc ca rnh ng (c to ra gia cc hp) l nhng khay cha. Cc khay c y mt co nhm ngn cn s vung vi mi trng khi np. Phng c trang b cc khp ni np hi, nc v thi nc ngng. My rung c bt cht vo phng tho d canh trng nm mc. Kim tra v ghi nhit c thc hin nh nhit k tip xc t ti mt trong nhng rnh nui cy v ni vi b dn ng qut, rle s t ng tt v m qut.

Nhc im ca loi ny l nng sut nh, bin dng cc phng v thi canh trng nui cy nm mc ra khi khay l rt kh khn, kn khi thi khng m bo v tiu hao khng kh thi nhit sinh lln.

Phng nui cy vi sinh vt trn mi trng dinh dng rn c cc hp tho c v d ti bng t ng ho.Thit b ny l s bin dng ca thit b kolovieva.Phng nui cy l hm kim loi, trong c lp cc hp ng c th tho d hm c. Phng c lp trn khung vi cc bnh v c th chuyn dch theo cc ray. c nh mt v tr xc nh phng c trang b cht nh v. Khay c to nn do hai bn khay c khp ni phn trn ca phng.Tay n iu chnh cc tm chn ph phn di ca cc khay. Thc hin thng gi canh trng qua cc rnh phn b khng kh trong cc khay. C cu tho d (hnh 9.1) canh trng nui cy ra khi khay c phn b trn phng nui cy v gm nhng b phn c lin quan nhau c nh cc khay 2; c cu m cc khay c phn b tng xng theo hai hng ca phng; c cu y phng n tm kim loi phng nm ngang 6 c kp cht bng cc thanh ni ng 7 chuyn ng quay tnh tin. Cc b phn nh v cc khung 2 gm hai trc (c cc cht) sp xp song song cn i vi trc ngang ca phng. C cu m ca cc khay c hai mm quay vi cc thanh truyn, thanh rng c kp cht trn cc thanh truyn c phn b t hai hng ca phng v dng chuyn dch phng. Tt c cc c cu trn c lp cht trn sng 9. Sng ta trn khung 3 nh ct 8. ng c in lm chuyn ng thit b. Phng cng vi canh trng nui cy chuyn di theo ng ray 1 tho d v c nh v mt v tr nh. Sau dng tay

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n m tm chn ca khay, cn tay gt m khay u theo tin trnh tho d. Khi m ng c in, thanh rng c cht 5 bt u chuyn dch, phn di ca na khay dch li ra. Sau c cu y bt u hot ng: tm kim loi 6 h xung di, y canh trng nui cy ra khi khay v c nng ln. Khi tm kim loi nng cao hn khay, sng bt u chuyn dch theo khung 3 nh ct 8 vo v tr trn khung tip theo. Tr chng 4 cng vi sng chuyn dch v khi tc ng ti cht, a n vng bin, ti y khay c tho d theo th t.

Hnh 18. C cu tho d t ng canh trng nm mc trong cc hp ra khi phng: 1- ng ray; 2- Cht nh v; 3- Khung; 4- Trng; 5- Cht; 6- Tm kim loi phng; 7- Thanh ni; 8- ct; 9- Sng; 10- a xch

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Khi thit b c 7 phng nui cy c th thu nhn 1200 kg ging nm mc trong mt ngy. Cc phng nui cy c ch to bng hp kim nhm, sc cha ca chng 500 kg, kch thc c bn ca phng 160013001020 mm, khi lng 771 kg.

Dy chuyn t ng ho nui cy ging nm mc. Trn c s cc phng nui cy vi sinh vt trn mi trng rn c cc hp tho d, tho ra qu trnh lp rp v vn hnh dy chuyn cng ngh nui cy bng c kh ho v nhn c nhng ch phm enzim tinh khit c cng sut 50 100 tn/nm, ph thuc vo dng ch phm sn xut. Dy chuyn gm cc cng on: chun b mi trng dinh dng, nui cy, trch ly, lng, tch v sy, tiu chun ho v gi ch phm. Giai on quan trng nht ca dy chuyn l chun b mi trng dinh dng v nui cy ging nm mc, gm hai bng chuyn cng ngh c lp nhau (hnh 9.2).

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Hnh 19. Cng on nui cy ging trn b mt: 1- Vng trn quay; 2- C cu y; 3- Thit b san; 4- Rnh np liu; 5- Bn np

liu ; 6- B tit trng cc phng nui cy; 7- C cu y; 8- Ra cc phng; 9- Bn d liu; 10- Phng nui cy; 10- Bra khp cui cng; 12- Bng ti; 13- Phng nui cy mi trng rn; 14- Bulng ghp; 15- ng ray

Trong mi bng chuyn u c b tit trng, ni khuy trn, 9 phng nui cy trn mi trng rn trong ng hm kn vi h ng ray 15 chuyn dch lin tc cc phng t cng on cng ngh ny n cc on cng ngh khc.

Vn chuyn cm v b c ci vo thng cha bng kh nn, ri cho qua vt ti vo mt trong nhng ni tit trng. Sau khi np vo ni tit trng mt lng nc v dung dch amoni sunfat nht nh ri trn u v tin hnh tit trng mi trng ch t ng. Sau mi trng c a vo thit b khuy trn tit trng. Nc lm m mi trng v huyn ph c ng ho vi lng 0,1 0,8% so vi khi lng ca mi trng dinh dng cho vo thit b khuy trn trn. Sau khi khuy trn trong vng 3 5 pht, ca np ca my trn t ng m ra v rt mi trng vo cc hp tho d c trong phng 13 di my trn trn bn np liu 5 ca giai on nui. Mi trng vo phng tit trng qua rnh m di ng c dng hnh nn, rnh phn b mi trng vo 28 hp. S m cht cc mi trng trong cc lp xy ra khi phng dao ng, sau theo ng ray t ng chuyn vo ng hm ca phng nui cy 10. Cng on nui cy c trang b hai phng nui cy 10 song song nhau, c 9 v tr thi kh, hai b phn np liu 3 v 4, b phn tho liu 9, nghin ging, ra 8 v tit trng phng 6. Tt c cc b phn ny ni nhau bi cc ng ray 15 c vng trn quay 1 v bi cc h thng vn chuyn nm bng ti xch v c cu y bng thu lc 2. Vic vn chuyn cc

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phng t b phn ny sang b phn khc u tin hnh bng t ng. ng hm ca phng nui cy c chia ra lm ba on: on u c phn b

lin tc cho 6 phng nui vi sinh vt trn mi trng rn s13, on th hai cho hai phng v on th ba cho mt phng. Cc on trong phng nui c ng kn bng cc ca kh ng hc c cc tm m cao su. Mi on c trang b hai ng khuch tn phn b ngc nhau. Cc calorife v cc qut theo h tun hon khp kn. C khong 3 h th cho phng nui cy c np liu vo ng hm, cn phng trc th t ng chuyn dch n on tip theo. Cho nn c 9 phng nui vi sinh vt trn mi trng rn c a vo ng hm ca phng nui.

cc on u vo thi k ca cc pha tin pht, khi xy ra sny mm bo t (thi gian t16 18 h) trong phng phi gi nhit 33 350C. Vo thi k pht trin (thi gian 16 h) cng ca dng khng kh c tng ln nhm bo m thi nhit v thi cc sn phm chuyn ho to kh khi gi nhit ca mi trng 35 360C. on th ba nui trong giai on tch lu enzim, dng h thng gi c tnh n gi nhit ti u 32 340C. Nhit ca khng kh trong mi on c iu chnh t ng theo chng trnh cho.

Khi kt thc chu trnh nui, c cu 7 y phng 13 ra khi ng hm v a n bn tho d 9. M c cu chuyn dch phng n bn tho d v xy ra s chuyn dch ca phng n mt khong cch bng chiu rng ca hp. Khi tay n ca y hp v tay n tho d hp t quay trn, v c cu y s y canh trng nui cy t hp n b nghin u tin. Sau khi d ti, phng nui cy chuyn ng theo ng ray n bphn ra, ri vo b tit trng.B tit trng l xylanh nm ngang c hai np m ngc chiu. Cc np c y kn nh b p thu lc. Sau khi tit trng phng c lm lnh, sy bng khng kh tit trng v t ng a n bn np liu, sau chu trnh cng ngh c lp li. Dy chuyn cng ngh t ng ho lm tng mc cng ngh v ging sn xut, lm gim thi bi v bo t.Tuy nhin n chim din tch ln lp t h vn chuyn v cc phng nui cy, tn nng lng v kim loi, nng sut thp.

Thit b nui cy ging bng phng php tnh ng i vi cc iu kin sn xut ln th cng sut n v ca thit b cn phi tng

ng k.Ngoi ra cng cn phi to ra cc thit b c nh nhm m bo kn ca tt ccc cng on cng ngh, gim din tch v khi lng ring. Phng php nui cy chng nm mc trn b mt tnh - ng lc hc l ch mi trng trng thi bt ng (trng thi tnh), cn sau chu s chuyn ng tun hon cng bc, lm ti v chuyn o (cc iu kin ng lc hc). Vi phng php ny khng th s dng cc

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khay c v mi trng s b ra ngoi. Mi trng dinh dng tit trng c trn vi ging vi sinh vt a vo gin bng ti u tin ca phng nui cy. Khng kh c pha trn s bvi hi nc bo ho hay l khng kh c iu ho y vo phng. Lng khng kh v hi nc c tnh ton sao cho trong vng tnh c nhit ca hn hp hi - khng kh 32 350C, cn m tng i- 96 98%.

Thi gian gi mi trng cy trn gin c xc nh trn c s ph thuc vo s sng trong phng. Khi thi gian chung ca ging pht trin trong tt c cc gin cn bng thi gian chung ca qu trnh nui cy ging (t 24 n 48 h). Qua nhng khong thi gian nh nhau, sn phm c chuyn bng c kh t gin trn xung gin di k cn. Cc gin trn c s dng cho pha nui cy u tin, cc gin gia cho pha th hai v cc gin di cho pha thba. Cho nn mi trng dinh dng c cy, khi chuyn t gin ny sang gin khc xy ra tt c cc giai on pht trin. Vic np cc l mi trng dinh dng mi ln gin trn cng ca phng vi khong bng thi gian c mt ca mi trng trn mi gin ca phng. Phng php nh th cho php s dng ti a th tch hu ch ca phng, cho php tng cng qu trnh v lm d dng iu kin lao ng. Khi chuyn t gin ny sang gin khc mi trng c lm ti nhm tng cng cc qu trnh thng gi, thi cc sn phm chuyn ha to ra kh v nhn c ging c hot ho cao. Cc iu kin trao i nhit cng c tt hn, cho php gim tiu hao khng kh thi nhit sinh l. Vic nui cy cc ging vi sinh vt bng phng php tnh - ng c kh nng tin hnh trong cc thit b dng bng ti vcc dng khc.

Thit b nui cy vi sinh vt trn mi trng rn dng -42-. C cu bn trong thit b tng t nh kt cu my sy dng -42- v c tt c cc b phn ph: calorife, qut, xyclon v ng thng kh, cng nh c cu lt cc gin trong phng v lm kn khu np mi trng n gin u tin. L sy t ng tc dng lin tc -42- gm c phng sy, hai calorife, ba qut v ba xyclon (xem hnh 9.3).

Thit b (hnh 9.3) gm phng sy 7, hai calorife 4, ba qut 1 v 12 v 3 xyclon 2. Phng c khung kim loi 11 c bc bng st l v c bao ph lp cch nhit. Bn trong phng phn b 20 gin nm ngang c nh, khong cch gia cc gin theo chiu cao 120 mm. Mi gin c16 bn ring bit 8 vi kch thc 12060 mm, cc bn t ng quay mt gc 900 trong khong thi gian cho.

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Hnh 20. L sy dng ng -42- Khi sn phm c tho xung cc gin di cn cc gin lt c quay v v tr

nm ngang ban u. Nh cc tm ngn bn trong m phng 7 c chia ra lm ba phn nhm cho php s dng hp l s phn b tc nhn nhit theo cc vng sy. Trong vng u phn trn ca phng c phn b 6 gin, trong vng th hai phn gia - 8 gin v trong vng th ba vng di- 6 gin. phn sn pha trc ca phng c cc ca 9 ni vi ng vo t do. Cc ng thng gi t hai qut 12, calorife 4 v ng ra ca tc nhn nhit ti qut ht 1 (qut ht th ba) v ti cc xyclon 2 u c gn phn sn pha sau. S quay cc bn ca gin c tnh n sao cho ton b thi gian sy l 5 10 pht. Sn phm t c nghin cho lin tc qua thng cha vo thit b np liu v c t ng ri u thnh lp nm gin trn ca phn sy. Bm ly tm 12 ht khng kh qua blc th 14 v lc tinh 13 ri y vo phng sy qua calorife 4, ti y khng kh c un nng n 85 900C. T gin cui cng sn phm th c np vo thng cha 10. Khi i qua cng hng vi vt liu sy trn cc gin

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6, khng kh c hng theo knh chuyn tip gia cc gin lm thay i hng chuyn ng (ngc chiu) v sau thi ra ngoi. Nhit khng kh sau khi qua calorife trong cc vng c kim tra bng nhit k 3. Dng m k 5 o m ca khng kh vo phng. Qut 12 y khng kh vo vng pha di ca mng sy vi nhit 60 700C nhm sy thm sn phm n hm m 10 12%. Qut x hi 1 ht khng kh thi qua cc xyclon 2 v c thi vo kh quyn, cn cc ht ca vt liu sy c tch ra v theo mc tch lu m thi ra ngoi theo chu k. Trc khi thi khng kh vo kh quyn cn phi lm sch trong cc b lc th 14 v lc tinh 13. Vi mc ch thch nghi cho my sy dng nui cy chng nm mc, khng kh c ht theo ng thng gi c t cao hn sng mi thit b khong 4 5 m, c lc qua b lc th, lc vi khun v c ho ln vi hi nc bo ho trong ng thng gi t c cc thng s cng ngh quy nh (nhit 32 330C v m tng i 96 98%). S dng cc b lc vi khun lm sch khng kh thi vi khun. Vo thi gian tit trng my sy th b lc ny ngng hot ng. Trong tt c ba giai on, ch vo v ra ca khng kh u t cc nhit k t ghi kim tra nhit v m ca khng kh v mi trng. Np mi trng dinh dng c tit trng ln gin trn cng ca phng phi c bt kn. Bng ti vn chuyn phn b mi trng theo gin. Nhit c thit lp vng hai v vng ba 27 290C. Cho nn sau thi gian chuyn dch ca mi trng c cy theo tt c cc gin th s pht trin ging nm mc v s tch lu cc enzim c kt thc. Mi trng nui cy nm mc ra khi gin di cng ri vo b cha, sau em nghin v sy. 24 27 kg mi trng tnh quy ra cm kh np vo gin di ca phng, v sau mt ngy c th nui n 300 kg canh trng nm mc. Khi kt thc nui cy phi ra phng thit b bng nc nng v tit trng bng khng kh c un nng n 120 1300C. Thit b nui cy vi sinh vt trn mi trng dinh dng rn kiu bng ai.

Thit b dng KCK (hnh 9.4) l t kim loi, bn trong c 4 5 nhnh bng ti vn chuyn dng li, c ch to bng thp khng g vi cc mt li 21,5 mm v c cng ra trn hai tang quay. Kch thc ca cc bng vn chuyn ph thuc vo dng my sy. Mi bng ti hoc l c hp tc ring hoc l dng chung mt hp tc . Hp tc thay i tc ca bng ti t 0,14 n 1,0 m/ph. Trn cc bng ti vn chuyn c cc thanh nhm phn b ng u lp mi trng dinh dng c chiu cao t 30 n 100 mm. lm ti mi trng, pha trn bng ti lp t cc trc c cc cnh hnh kim, c quay cng hng vi bng ti. Vic lm ti c tin hnh khi chuyn ti mi trng t bng ti trn xung bng ti di. Di cc nhnh khng ti ca bng ti vn chuyn t cc b lm sch. Cc trc ca b lm sch c cc cnh nh cht cc thanh cao su, quay ngc hng chuyn ng ca bng ti. Trong khng gian gia cc

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nhnh ca bng ti lp t cc calorife hi nc. i vi mi bc tng calorife ca cc vng nui cy th nht v th hai u c cc

thng c bit chun b nc nng v c dng c iu chnh v kim tra nhit . Nhit nc a vo calorife di cc nhnh mt v hai ca bng ti 35 400C, di cc nhnh ba v bn 26 300C. Cc calorife ca cc nhnh bng ti 5 c th c un nng bng nc nng thi ra t cc nhnh trn. Cc calorife u c khp ni cung cp hi nc cn thit cho vic un nng khi ra, sy v tit trng. C ba vng c to ra trong phng nui cy: vng trn c nhit mi trng 32 350C, vng gia c nhit 300C, vng ny xy ra thi nhit sinh l v vng di c nhit 280C. Thit b cn kn hon ton v c lp trong phng cch ly. Trn thit b lp ng ht gi c chiu cao 5 10 m cung cp v thi khng kh. Trn ng cp v ht cn lp t cc b lc lm sch khng kh khi vi khun.

Dng bng chuyn nghing ng kn hoc l dng ng t chy t ni tit trng t trn thit b chuyn mi trng dinh dng c tit trng n bng ti trn cng. Lng khng kh cn n 1000 m3 cho 1 tn canh trng nm mc. Sau khi np mi trng dinh dng c cy ging vo nhnh trn ca bng ti vn chuyn, tt b dn ng bng ti v mi trng c gi trong thi gian 9 h. Sau n c vn chuyn n nhnh tip theo ca bng ti, ng thi vi vic lm ti khi mi trng v cng c gili trong 9 h. Vo thi gian ny l mi trng mi c vo nhnh trn. Cho nn c qua 9 h mi trng c chuyn xung nhnh di v qua 36 h tho canh trng nm mc dng thnh phm.

Khi kt thc chu trnh nui cy, ra t hp nui cy bng nc nng vtit trng bng khng kh nng nhit 120 1300C trong vng 2 3 h, sau lp li chu trnh cng ngh. C th np liu 600 700 kg mi trng dinh dng (270 300 kg tnh chuyn i ra cm ti dng kh) vi chiu cao ca lp mi trng 50 mm trn mt nhnh bng ti ca my sy.

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Hnh 21. Thit b nui cy vi sinh vt trn mi trn dinh dng rn kiu bng ai: 1- Qut; 2- B lc dng peca; 3- Lc vi khun; 4- My iu ho; 5- Phng nui

cy; 6- Bng li; 7- B lm ti; 8- Calorife; 9- Khng kh; 10- Thit b tit trng; 11- ng chy; 12- Bng chuyn

Thit b nui cy vi sinh vt trn mi trng rn rng rung Cc thit b c s dng trong cng nghip u c da trn phng php ng

lc hc nui cy canh trng nm mc trong lp rung ng lin tc. Bn cht ca phng php l ch: trong qu trnh nui cy mi trng dinh dng trong b phn vn chuyn c nhng tnh cht c trng (tr nn linh ng hn, h s ma st gim v sc cn gim xung). Xung lng dao ng s truyn cho lp mi trng ang vn chuyn v mi trng chuyn sang trng thi l lng.

Ch vn chuyn bng phng php rung c c trng bi s i mi lin tc lp b mt: mi trng tip xc vi bmt ca b phn ti vt, sau ri khi b mt, qua mt khong thi gian n li ri xung, cui cng b chuyn dch mnh. Mi mt tiu phn ca mi trng b chuyn ng lin tc trong vng 36 h, khi nhng tiu phn ring r nh nht c thi mnh lm cho b mt hot ho ca mi trng tng ln hng ngn ln so vi phng php nui cy tnh trong khay.

Nhit sinh l do vi sinh vt tch ra trong qu trnh pht trin log c thot ra ngoi, do tiu hao khng kh iu ho gim xung t 20.000 n 500 m3 cho mt tn canh trng. ng dng phng php rung cho php tng cng cc qu trnh trao i nhit, trao khi v tng hp vi sinh, cho php c kh ho tt c cc cng on, cho php tng hot ho ca ging v t chc qu trnh c kt qu cao.

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Thit b rung c th dng ng hay nm ngang. Thit b rung dng vt tc ng lin tc c nng sut 3,5 tn/ngy (hnh 9.5) gm ni

tit trng dng rung v bn bng ti rung c ph kn dng mng 7. Ba bng ti u tng ng vi cc vng pht trin th nht, th hai v th ba l phn nui cy trong thit b, cn bng ti th t dng sy canh trng. Mi bng ti rung c trang b b dn ng c lp vi my rung bt cn i.

Mi trng c sy t ni tit trng rung 3 vo mng nhn 6 ca bng ti rung th nht v di nh hng ca xung lng rung truyn cho mng, c chuyn di t di ln trn. T mng trn ca bng ti rung u tin, mi trng theo mng vo ng nhn di ca bng ti rung. Bng ti rung th hai v kt cu khc vi bng ti rung th nht ch ch: cc mng ca n c trang b o nc dn hi thot ra vo thi k pht trin log ca vi sinh vt. Khng kh iu ho c y vo bng ti rung th hai dn cc sn phm to ra trong qu trnh hot ng sng ca vi sinh vt. T mng trn ca bng ti rung th hai, mi trng theo ng vo mng nhn di ca bng ti rung th ba, c cu ca bng ti rung th ba tng t nh bng ti rung ban u. Tc chuyn ng ca mi trng theo mng ca bng ti rung 23 mm/s, cn ng knh v s vt ca tt c cc bng ti rung c tnh sao cho mi trng c chuyn ng lin tc trong thi gian ca tt c cc qu trnh pht trin. T mng trn ca bng ti rung th 3 canh trng ca nm mc c nui cy theo ng vo mng nhn di ca bng ti th bn ri a i sy. Kt cu ca bng ti rung ny ging nh bng ti th hai, nhng np nc c nhit 700C vo o ca mng v cp b sung khng kh c nhit 70 800C. Canh trng nui cy nm mc sau khi sy c d ti, cn khng kh sau khi lm sch vi khun c a ra ngoi kh quyn. My iu ho np khng kh tit trng thng gi vi mt lng 500 1800 m3 cho mt tn canh trng.

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Hnh 22. Thit b nui cy t ng ho dng vt tc ng lin tc: 1- Khung thng cha; 2- Thng cha cm; 3- Ni tit trng rung; 4- Dn ng

rung; 5- Ni tit trng; 6- on ng np mi trng dinh dng c tit trng; 7- Bng ti rung dng vt; 8- Dn ng; 9- ng np mi trng n bng rung th hai; 10- ng np mi trng n bng rung th ba; 11- ng np mi trng n bng rung th t

c tnh k thut ca thit b rung nui cy vi sinh vt trn mi trng rn dng vt:

Nng sut tnh theo thnh phm canh trng, tn/ngy

(khi thi gian pht trin 36 h): 3,5

Gc nng ca mng vt (theo ng knh trung bnh): 504

Bc mng, mm: 219,2

ng knh mng, mm:

ngoi: 2000

trong: 1000

trung bnh: 1500

Chiu rng mng: 120

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Chiu cao mng, mm: 500

Tn s dao ng, Hz: t 5 n 26

Bin dao ng, mm: 5

Gc hng dao ng: 8701 ; 890 30

Cng sut ng c, kW: 28 40

Kch thc c bn, mm: 510080007200

Khi lng, kg: 16.000

Thit b dng thp Thit b nui cy vi sinh vt v ng. Thit b dng thp nui cy vi sinh vt

(hnh 9.6) gm v ng 15 c chia ra lm 6 khoang vi cc cnh hng tm c vi phun khng kh 6 c lp trn trc rng 13 v vi cc tm t l 16 c g trn cc trc quay 2. Thit b c ng xon lm lnh 5, ng gp np khng kh tit trng 4 v ng gp thi kh 7. phn trn ca dung lng c ca np liu 14, cn phn di c ca tho canh trng pht trin 1. Phn gia ca dung lng xy ra thi k pht trin log ca vi sinh vt km theo tch nhit nn c trang b o lnh 17. B dn ng qua bnh rng 12 lm cho trc 13 quay.

Np mi trng tit trng c cy ging qua ca 14 vo thit b tit trng s b.Mi trng c phn b u trn din tch cc tm t l 16 ca khoang u tin nh cc cnh 6 lp trn trc theo chiu cao ca thit b. Khi kt thc pha u ca qu trnh (qua 6 h) cc tm t l chuyn vo v tr ng. Mi trng ri vo khoang hai v cc cnh s gt thnh lp u trn b mt ca cc tm t l. L mi trng mi li c np vo khoang u tin c gii phng. Qua 6 h, mi trng t khoang hai c tho vo khoang 3, cn t khoang u vo khoang hai. Mt ln na khoang u li c np y. Cho nn tt c 6 khoang ca thit b c np y. Qua 36 h sau khi np mi trng vo khoang u, d canh trng v a gia cng tip theo. Qu trnh xy ra mt cch lin tc. Trong tin trnh nui cy, khng kh c a vo thit b vi sinh vt h hp. Dng nc trong rut xon 5 v trong cc o nc 17 thi nhit sinh hc do vi sinh vt thi ra. Vic np nhit vo khoang trn cha mi trng mi c thc hin bng phng php thi khng kh m c un nng khoang nm di qua lp mi trng. Khi cn thit th np khng kh tit trng qua trc 13 v cc cnh 6 vo thit b to dng ri. Tit trng thit b p sut 0,3 MPa trong vng 1,5 2 h. Khi nui cy ging trong thit b kn v khi thng kh qua cc tm t l, dng kh trong mi trng s gy ra s gim p sut v kt cu rng ca mi trng dinh

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dng. S chuyn ng ca kh trong trng hp ny khng phi xy ra dc b mt ca lp mi trng m n lan rng trong khp th tch, kt qu l to nn ch thi khi c kh nng trao i khi v trao i nhit bng i lu v khuch tn theo khp chiu cao ca canh trng pht trin.

Hnh 23. Thit b nui cy vi sinh vt trong lp mi trng c chiu cao 300 mm

1- Ca tho liu; 2- Cc trc quay; 3- Gi ta; 4- ng gp np khng kh tit trng; 5- ng xon lm lnh; 6- Cnh trc; 7- ng gp tho khng kh thi; 8- Np ; 9- Khp ni cm p k; 10- Khp ni; 11- ng thot kh; 12- Bnh dn

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ng dng phng php thi khi mi trng dinh dng cho php tng chiu cao ca lp canh trng khong 10 ln hay ln hn v to ra nhng iu kin ng dng thit b nui cy su. Tng chiu cao ca lp mi trng t 20 40 n 300 500 mm l mt trong nhng hng chnh tng nng sut thit b cng ngh, khc vi cc dng thit b c nu trn, tt c cc qu trnh v cng on cng ngh c c kh ho, loi tr s tip xc ca cng nhn thao tc vi canh trng v cc sn phm chuyn ho ca chng. Trong qu trnh nui cy, nhit , m mi trng v khng kh, s vng quay ca my khuy, hm lng CO2 vO2 trong pha kh l nhng thng s cn iu chnh.

Thit b nui cy lin tc cc chng nm mc Loi thit b ny m bo khuy trn v lm ti tt c b dy ca mi trng trong

qu trnh nui cy, ngn nga kh ro ca cc lp bn trn, cng nh tng cng qu trnh. Thit b nui cy nm mc (hnh 9.7) gm thng cha mi trng 1, thng chun b vt liu cy 6, ni tit trng 2, c cu lm lnh v lm m mi trng 3, c cu cy ging 4 v thit b nui cy 5.

Thit b nui cy (hnh 24) c dng thp c ngn bng nhng on ng tn vi