microb bacteria

8/6/2019 Microb Bacteria

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fJ^'hv"t'n".:BACTERIAThe prokaryotesorganisms ithout a cellularnucleus) onsistof two domains or empires),"Bacteria" (or "Eubacteria") and "Archaea" (or "Archaeobacteria". They believe that thekingdomsArchaea and Eubacteriahad a commonancestorbut sepamted ery early on, a fewbillionyears go.

Comparisonlof Eubacteria and ArchaeobacteriaProDertisNucleuswith nucleolusCell wallMmbrane ipidGasvesiclsTransferR-flA

Polycistronic mRNAnRNA intronsnRNA Splicing,Capping,and Poly ATailingRibosomesSizeSensitjvity o chloramphenicol ndkanamycin

DNA-depesdent NA polymeraseNumber fenzymesStructuroRifampicin nsitivityPollmerose I Tjpepro,nole8Metabolism

Similar ATPaseMethanogenesisNitrogenixation

ChlorophJ'l- basedphotos!nt rcsis

ubacteriaAbsentPeptidoglycan containingmuramic cidEster-linked, traight-chairredfatry acidsPresontThymine present in mosttRNAs, N-formylmeth;oninecarried y nitiatorPresent

ArchaeobacteriaVarietyoftypes,no muramic cidEsterlinked, ranched-aliphaticcidsPresentNo thymine in I-RNA Methioninecarried y initiatorPresent

70sSensitive

70sInseDsitive

OneSimple ubunit attemSensitive

No

Present

Present

SeveralComplex ubunit attemlnsensitivePresent

PresentPresent


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ARCHAE (Archaeobacteria)They re heone-celledrsanisms'anv.of hich.do""t ':qilT :119"-l-l.::ii-"T :.:'J,i:il::il###";;,,i1""il" g'"i,p"Jlo, bactfiaecauseikebactoria'hevacrawell-delhcd nucleus. rohae acteria rc sinilar to eucaryotes iththeRNAandprotein ynthetic ,\stelt}s'Classificationof Archaeobacteria:

rcspoc1o some omponentsf

1.Thermoacidophilesl hey ive in theextremely ot 'acidicwaterandmoistareaswithin and."."mat* ""ff,i. ft*.prings Soctosely dapte'Lre hey o theirbubblynvironnenthat hy

ii" "if.iJiat"-**t.". oi ss"c 1l : t'n) eg' ThermoPlasm'ernococcus'vrococcLLt

2.Methsnogens:he)areobligalenaerobe'ree \-\ en il l ' -their .hich \ idi/eCO:dllr ing.. i1"f", *pit , i- lo produce elhaneCH't asa sasteproducL lthough NA sequenclngsulgestsrratl reu no*npeciesr.-..J::,li:T,iJ",l::::i*il:f +illJ*:1"J'":;Lliversesscaldingolcanic eep-reaenI!i"fri "-o"fi "i n^tif*"e (should ouchooseo go ntoshoubusiness)s becausef the

svmbioticrn_ethanoeensnsideyout guts Eg-Methanobdcterium'Methonococcue3. Strict halopbiles: hey ive in extremelv altvsolutionsuchas heDeadSea' heGreatSalti;rti- ""a dt"i can of pickled herringyou leff open n the cupboard

Their pink carotenoidoieor"ntaut" tft"a "onspicuouswhen hebact"tiu t" pt"t"nt in large oncentrations'

s hey;:';;; il;;;. "i '"-e ;ltv' landlocked lakes Es Eatobactefium'HatocoLcusEUBACTERIABacter iaweref i rstobselveclbyAntonlevanLeeuwenhoekin16T6,usingasingleJensili".""*ti "i frit "*t J"sign.He called hem unimalcules"

ndpublished is observationsn a."r-i* "ii*"tt," trt" noyaiSocietyTheyare he ruebacteria'ne-celldrganisms' n average;;;;;t, "il;;" ;ilrometei long.Theperfecrmedium environmenr).for

rowingbactenail;';;; il. the kitchen' although its Lisefulness as iemonstmted irl the laboratoryof1"r.""--""i""iir, ["un Kocir.Themedi,rmwasagar, gel-forming ubstancehatcomesromseaweed.


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slo16ge ranule

cgioprasmicinner,pept idogrucan

flagellrm

TgpicalGram-Negat iue

Composition fa Tynical BacterialCellBacteriaareabout70oZwater. The other 30o% the drv weisht - consistsof:

aminoacidssusals

I 0 ier.tn".Jr^tdtr-+L"pl-,.I p"nto.".

weight solutesF;;"1""'1".I Inorganrcons

o. t ' . r @. '_rt_.- . -- . . .Q.

Polysaccharide


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Classification f bacteriaBacteria remainlyclassifiedntophylumsphylum s a scientific lassificationf organisms).For simplification,acteria anbegouped nto he ollowinggroups:

Basedon shapes:Rod shapedBacilli): ,4ztcobacterid,Pseudomollas, almonella,ClosttidiumBotulinumEscharichia,Shigella,Proteu, Etwilxia, Yercinia,E terobacter,SerratiaSphercCoaci) : Chlamydia,Staplrylococclts, treptococciSpiral andci: ed bacteia: Spirillum,Auqaspirillum'Oceanospirillum,Bde ovibrioBased on oxygen requirement:Aerobic and Anaerobicbacteria:Bacteriahosneedor"vgen or their survivalare calledAerobic acteria.Eg. Azotobacter,Mizobium, Nitrosomonas,Nitrobacter'miobacillus, Pseudomonas'egionella'Anaerobicbacteriacannot bear oxygenand may die if kept in oxygenated nvironment(anaerobicactea are or:nd n placesike under he surface f earth, eepooean' ndbacteriawhich ive n somemedium).EE.Clostr lium, Desulfotomaculum, dmpylobacter, rmomonas,Aerc)morasbasedon Gram-stainingmethod:Gram-pos;tiye acteria:This division ncludeshegram-positiveods,gram-positiveocci,andthe actinomycetes,which exhibit superficial similarity and functioD (but no evolutionaryrelationship)o the (eukaryotic)ungi.They areusually hemoorganoheterotrophic.hick cellwalt with multiple peptidoglycM layers. No outer membrane,pedplasmic space orlipopolysaccharide.heypossessongchain eichoic cids ntellwined monghepeptidoglycan'Eg.Streptococcus,euconostoc, ctcillus,Closftidium,Loclobacillus,Propionibactefium'Gram-negative acteria:About 75%of knowneubacleriarcgmmnegative. hey ncludetheglidingba'cteria,he spirochetes,he curved vihios) and spiral spirillae)bacteriaSingle hinpeptidoglycan ayet but no teichoic acids. Possessan outer membmnecontainingiip;polysaccharidend a periplasmic pace etweenhe outerand innermmbraneshey arpir"i.t-pfti", chemolitho;uto;ophic r chemoorganoheterohophicg Brucella, Bortletellapo"t"*itlo, Haemophilus, Escherichid, Shigella, Salnonella' Prcteus, Erv)inia, Yersinia,Entelobacter,Serratia


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Based nphyla:

4.5.6.

l. PHYLUM AQUIFICAE: Containautotrophicacteriahatcan use hydrogenfor eners/ production.Eg.Aqui,fexandHydrogenobacter2. PHYLITM TIIERMOTOGAE: They areanaerobic, hemophilic, fermentative,$am-negativebacteria hat have unusual atty acids with respect o their ether-finked ipids.Eg.Thermotoga-?utoga.3. PHYLIJM DEINOCOCCUS-THERMUS: cram positive and have highconcentrationof carotenoidpigments,which may prcJect t from radiationandunique ipids.Eg.Deirococcus, hermw.PIIYLUM THERMODESIILFOBACTERI{: They are the small group ofsulphate educing hermophilic bacteria.Eg. fremodesulfobaclerium.PHI'LI'M CIIRYSIOGENETIS: Curved, rod shaped,gram-negativeandstrictly anaerobic.Eg.Crryrogerer.PIfYLf,T4 CHLOROFLE)O: Carry out anoxygenicphotosynthesisand is agliding bacterium.Many membeNof this gram-negative roupare calledgreennon-sulphurbacteria.Eg.Chlorolexus, HerpetosiphonPHYLIIM TFERMOMICROBIA: Groupof thermophilic greennon-sulphur-bacteria.. g.Sphaerobacteriermophil*,PIIYLIM NIIROSPIRA: Thesebacteria onvertammonia o nitrites andnitrites to nitrate. They are important in marin habitats Eg. Nitrospira,

7.8.

Nitos omonas,Nitrococcus.9. PIfYLUM CYAIIOBACTERIA: Cyanobacteria include unicellular andcolonial pecies. oloniesmay orm ilaments,heets r evenhollowballs.Somefilamentous colonies show the ability to differentiate into seveml different cellmes: vegetative ells, he normal,photosyntheticells hat are formedunderfavourable owing conditions; kinetes,he climate-resistantpores hat mayform when environmentalconditions become harsh: and thick-walledhelerocysls.ahich onlainheen4menilrogenase.iral tor nitrogeni\arion.Eg. Anabae a, Nostoc,Calothrix10.PHYLIJM CHLOROBI- Green sulphur and anaerobic photoautotrophicbacteia. Eg. Chlorobium,A cnlochloris11.PHYLIM PROTEOBACTERIA:Thephylum s divided nto 5 classes:Afphaproteobacteria: They include oligotrophic folms Meth)lobactefiufi,Nitobacter, RhizobiunBetaproteobacteria: hey tend to use substanceshat diffuse flom organicdecornposition n the anaerobic zone of habitats eg. Nitrosomonas,MethylobacillusGammaprotdobacteria: They often are chemoorganotrophic,acultatively andfejJinentative. g. Me iy lococcus,ChromatiumDltaproteobacteria: Consistofvariety of anaerobeshat genemtesulfide fromsulphate ndsulphurwhileoxidizing rganic unients g.DesulfaibfioEpsilonproteobacteria: espite ts smallsize wo important athogenicenraareCampylobacterandHelicobacter

12.PHYLIJM PLANCTOMYCETIS: Theyarecoccoid o ovoid or pearshapedcells hat lackpeptidoglycan.Eg. sophaera13. PEYLIIM CHLAMYDIAEi They arc intracellularparasitewith no appendagesEg. Chlamydiae


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14.PHYLUM SPIROCILA.ETES:ontain elicalty haped, orile,gram-negativebacterjaand arechemoheterctrophsg. f/epore na andBoftelia15.PHYLUM FIRMICUTf,S: Mostly heyaregram_positivendheterotrophicndhave low G+C contnt Eg. Clostridium, Desulfotomaculum, Bacillw,lut robac l u5.Sftepto.occut-16. PHYLITM ACTINOBACTERIA: High C+C grarn positives often folmcomplex branching hyphae and produce lmge mycolic acids Eg.Corynebacterium, rankia,Actinomlces,MicrococcusECONOMIC IMPORTANCE OF BACTERIA

Theeconomic mportance f bacteriaderives rom the fact thatbacteriaareexploitedby humansin a number f beneficialways.Despite he act hatsomebacteria layharmful oles,suonascausing isease ndspoiling ood, heeconomicmportancefbacteriancludes oth heirusefulandharmfulaspects.l. Bacteda, often ,a ctobacillus n combinaton \r,ith leasrsand molds.have beenused

jn the preparationof ferrnentedoods suchas cheese, ickles. oysauce, auefl


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-_q+

Bwbacterium longum

2. Nitrogen-fixing acteriasuchas heseR izoDirlr?p.) nhabit he foot cellsof plarts n thelgume family (Fabaceae).These moneran symbionts convet gaseousnihogen from theatmosphere N2) into usable "fixed" nitrogen (ammoni4 nitrite and nitrate) which can beabsorbed y the rootsand usedby theplant o manufacture roteinand nucleicacids.3. In the chemical ndustry, bacteriaare most important n the productionof enantiomericallypule chemicals for use as pharmaceuticalsor agrochemicals. Pharmaceuticals, uoh asantibiotics,vaccinesand steroids.Other bacteri4suchas these ttepromJcesspp., !re sources flife-savingmedicins. hisgenus ields hepowerfulantibiotic nownas streptomycin.t killssensitivemicrobesby hurting cell membranesnd nhibiting proteinsynthesis.Streptomycins anantibiotic that inhibits both grampositivea.ndgramnegativebacteria and is a thereforca usefulbroadspectrum ntibiotic.Actinomycetes re he sourceof actinomycir thereby ncrecsinghe acidity ofthe intestinesandinhibiting bacterialvillains suchasC/osfTdion, Saltunell4 Shigella, id E. coli.New antibiotic producedby Bacteia-Bacillus, .e, 5-, FD-Xylofuranosylneaminewhich is activeagainstgram-positiveand somegran-negativebacteria-Lactobacillus acidophilus can suppress he formation of cancer-causing mines and cancer-promotingnzrmes n the intestinFsof humansand animals.Producea wide range of antibioticsubstancesacidophilin,acteriocin, tc.)whichhelpcontrol he evelofpathogenic acteria ndft1n91uchas Candida.Produce itamins, especiallyB-vitaminsand vitamin K and act as bariersto preventpathogenic acteria rom colonizing he intestines4. GeoeticengineeringBacterialcells are ransforrnedand used n productionof commercially mportantproducts.Theexamplesare production of human insulin (used against diabetes),human gro*th hormone(somatotrophin sed o treatpituitary dwarfism), and infections 'r'hichcan be used o help fightviral diseases. sing biotechnolos/ echniques, acteria an also be bioengineeredor theprcductionoftherapeuticproteins,suchas nsulin,gro\'\4hactors or antibodies.

5. Fibre ettingBacterialpopulations,espcially hat of Closttidium butyclicum, arc used o separate ibres ofjute, hemp, la4 etc, he plantsarc inmersed n waterand when hey swell, noculated ithbacteriawhich hydrolyze pectic substanceof the cell walls and separate he fibres.Thesesepamtdibrcs areused o make opesand sacks.6. Vitamin s'.nthesisEschedchiacoli that lives in the human arge intestinesynthesize itamin B and release t forhuman se.Similarly,Clortridiumbulyclicums used or commercial reparationfriboflavin,avitaminB.


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6. Waste isDosalAerobicandanaerobicacteda reused o decomposeewage asres. heybreakdownorgantcmattero hamlss, oluble ludgen seftlisource.imirarryoxicrremicilv#:i#i; i,T#":[tr,flXT:"fi:,: ;::*: :l"lilesticidesredisposed/ith heheh;fb:geneticngineeringech.,o.""nd;";-#ff:TJ"#::ffi K#"h* b"""";atedbvusinsThe ability of bacGria o degradea variety of organiccompoundss remarkableand hasbensecm wasteprocssirg,andbioremedialion.Ba"i".l" g"putf" oiaig."fi"g ttl-t],a1o"arUon. inetroleumreoftenused o cleanup oil srnoroohickry"ou",.an ii. uli".i;;il'illii.jr"i.?iiffffff":i).ijJ$fi:::#"1,::,;7.Pest onEolBacteria analsobeusedn theplacofoesticidesn thebiological estcontrol.ThiscommonlyusesBacilllts thulingiensis (also called BT), " C_*_p..i i-"'", "oii i*"ri'r! U#.ir_. rf,i,li:TilJ: *" asaLepidopteran_specificinsecticrue'unJei-1"J"'"".". '"i"i"""i ota *aIlarmful bacteria

. Somebacteriaare and act eitheras disease-causinggents pathogens) oth in

Gmm-negativeocci ;ncludehe Darhosenic,ly'e^rsela fieningiti.lis, n important auseofmeningitis ndsepticaemia.ni N. pinor"tr,.g*i""r.i",""',r#;;;;;;;"';;i:ff:Kffii::::TiHfi"Ji[l"jl],"asgangrene,etanus,pseudomembranousolitis andbotulism.Pseldomonas.M environmental aproph),teaturallyresistant o antibiotics,hasbecomean mportant ospital athogenSliral bacterianclude hesmall gastrointestinal athogen elicobacter hatcolonizes nestomach,eadiDgo gashicandduodenal"i*r'*a g;oi" "an""r, ;;Z;;;;;1;"",spp. hatcauseacutediarheaBorrelia duttoni and.B. recutmtis causechronicdiseaseof the skin oints andcentralT::],. :f*, Lyme disease B_ krydo* ). The Leptospira # ;;;;i; ;;;;r,causrng n.acutemenjngilis yndromehat may be acrompanied 5 .nrt fuitriaoohepatitis.TheLeptosphdarezoonoticagents ausingan acuierneninlitfa ay"ai"-" *r"tmay beaccompanedby renal ailureanJheoamrsProBioticsProbioticsaredietarysupplementsontainingpotentialrybeneficiarbactefiaor yeasts.probiotic isa natuml approach o chronic disestive aisoi.a"rsl"oo"tiputloo, 'a'l".i"n "i"iig"Ji*, ,"0,fr"effects f prorongedntibiotich;rapy). uny enurion,n"itur""ai i"".lpi," fr," iJ"a *" *,.

SalmonellaWihurplants ndanimals, r play ole n foodspoifage. g.C-to,lridiui boniinun,E.coti.

. The major pathogem pyogenes, Glam-positivecocci) an agentof soreandpneumonia.1T:,.:l**::''"".,",, as" "pii,i"* gii")i;":;;;;ilJffi "#ilfi:

\


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can causedamage o, or evendestroy, he balanceof probiotic bacteria n the body's digestivesystem.Potential nfits f probioticbactefia

. Prcvention f colon cancer- acteria xertanti-carcinogenicffectsby decrcasingheactivityofan enzyme allod0-glucuronidaseCholesteroloweringLowering loodpressureDecreasehe ncidence f respiratoryract nfections nddental ariesn childrenLactobacillus are also thought to aid in the in th treatment of Helicobacterpyloriinfectionsn adultsReducingnflammation ndhype$nsitivjtyesponsesImprovingmineral bsorptionPreventbarmful bacterialgrowthunderstress onditionEach apsule ontainsmore han2,000,000,000twobillion) organismsften beneficial trains:L. dcidophilus,L. bifidus, L. fiamnosus, L. plantarum,L- salirarius, B. longan, L. bulgaris, L.lactis.L. casei.L. brevisIt is theprobiotic friendly lora" hathelpusprocessur ood andkeep n balance utrefbctivebacteriaandpotentialpathogens.ncluding Cardida albican. Henry Tissier, also rom the PasteurIndtitute, as he first to isolate Birtdobacteriumromgut flom of breast-fed abies, nd herecommendeddministrationfbifidobacteriao infants ufferingiom dianhea.

,.MetabolismIn cont'ast to higher organisms,bacteriaexhibit an extremely wide variety of metabolicq?es.Bacterialmetabolisms classifidntonutritional rcupson the basis fthroe majorcriteria:hekind ofenerry used or gro\rth, the sourceof carbon,and he electrondonorsused or gro\i4h.

Nutritional types n bacte al metabolism' ' i ' ' ' ." ' Source fcarbon Examples

suifurPurple


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Lithotrophs

Organicmmpounds

Carbonmetabolismn bacteria s either heterotrophic,where organiccarboncompounds re usedas carbon sourcs,or autotrophic, meaning hat cellulax carbon is obtained by frxing carbondioxide. Tnical autohophic bacteria are phototrophiccyanobacteri4grensulfur-bacte a andsomepulple bacteri4 but also many chmolithotophio species,such as nitrirying or sulfur-oxidising bacteria.Energr'metabolismof bacteria s eitherbasedon phototrophy, he use of lightthroughphotoslnthesis,or on chemotrophy,he useofchemical substancesor energy,which aremostly oddised at the expenseof oxygen or alternative electron acceptors aerobic/anaerobicrespimtion).Finally, bactria are further divided into lithotrophs that use inoiganic electron donorc andorgaiotrophs hat use organic compoundsas electron donors. Chemotrophicorganismsuse herespective electron donors for erergy conservation (by aerobic/anaerobic espiration orfermentation)and bioq,nthetic reactions e.9. carbon dioxide fixaiion), whereasphototrophicorganisms se them only for biosynthetic urposes.Respirutory rganismsuse chemicalcompounds sa sourceofenergy by taking eiectrons lom the reducedsubstrate nd transferringthem o a terminal electronacceptor n a redox reaction.This reaction eleases nergy hat can beused o synthesiseATP and drive mtabolism. n aerobic organisms,oxygen is used as theelectronacceptor.n anaerobico.ganismsother norganic compounds, uch as nitate, sulfateorcarbondioxide areusedas electron acceptors. his leads o the ecologically mportantprocessesof denitrification,sulfate eductionand acetogenesis,espectively.Anotherway of life ofchemotrophs n the absence fpossible elechon acceptorss femlentation,where he elctrons aken fromthe rcducedsubstratesre ransferredo oxidised ntemediatgs ogenerate reduced fementation products (e.g. lactate, ethanol, hydrogen, buq' c acid).Fermentations possible,bepausehe energycontentof the substratess higher thanthat of theproducts,'ihich allows he organismso synthesise TP and drive their metabolism.Lithotrophic bacte a can us inorganiccompoundsas a source of energy.Common norganicelechondonorsare hydrogen,carbon monoxide,ammonia leading o nitrification), ferous ironand other reduoedmetal ons, and several educd ulfur compounds.Unusually, he gasmethanecanbe used by methanohophicbacteriaas both a sourceof elechonsand a substrateor carbonanabolism. n both aerobic phototrophy and chemolithotrophy,oxygen is used as a terminalelectronacceptor,while underanaerobic onditions norganiccompounds re used nstead Mostlitbotroplic organisms re autotrophic,whercasorganotrophic rganisms re heterohophic.

Orqanic compoundsl, , . , , " , , ' , I hermodesullobacter ia,t tlmonelerotnopns or -, ,-.-._L-..- c. -,:-- nyarogenopnu .(:eae,


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ReproductionBacteda eprcduceby a way of asexual eproductioncalledbinary fission wherebacteriasplitsinto two celis. Each cell getsan exactcopy of the parentcell's geneticmaterial.Under optimalconditions,acteda angroward divideexbenelympidly,andbacterial opulationsandoubleasquicklyasevery9.Eminutes-n cell division.wo identjcal tone augirtr ellsareproduced.Somebacteria,while still regoducing asexually,orm morccomplexrep;oductivestructureshathelp disperse he newly-formed daughter cells. Examples nclude fruiting body fomation byMyxobacteriaartdaial hphae formationby S'/ eptomrces, r brdding.Bacteriaalso eproducewith theexchange f DNA. WhenbacteriaexchangeDNA, it hasasimilareffect o sexual eproduction,n that, here s a blendingof genesbetweenwo organisms.Thereare lree ways n which bactedaexchangeDNA.

1. Conjugation malecellpassesDNAtoemale ellbymeans fa conjugationube sexpilus).2. Transformation bacterium akesup DNA released v deadbacteria.3- TransductionbacleriophagesarryDNA fromonecell to anotherMoyementMostbacteria oveby theuseofflagella.n some acteria,here s onlya singl lagellum tone end.suchcellsare calledmonotrichous. len single lagellum'presentt both ends'. calied as amphihichous and numerousflagella located at one end of the cll calledlophotrichous.lagella shibutedver heentire urface fthe cell calledasperitrichous.Glidingmovment: t is the movement f cellsoversurfacewithout he aid of flagellaeg.OscillatoriaChemotaxis movement: In it the actual rotation of the flagellum is controlled by proteincomplexesMethylaccepting hemotaxis rotein MCps) located n tbe basalbodyof theflagellum g.C.coli

SCIENTIFIC STIJDY OF BACTERIARecent nformationo.l the true diversitv of bacteriacomes ronr Astudypublished n 2006 thatuseda new DNA-identificationechniqueo studymicrobes akeo i"om le ocean.ScientistsfoLrrd$re than20,000 ypesof bacterjan a Ijterof sea rater--ver ten imes heb;odiversifypredicigd.Much ofthe dt'versitycame rom rare bacteria hat had not bendetected n previoussfudiesof marine micaobes.Samplesweretake11t eight sites n the Atlantic OceanandpacificOceaniom a wide alge ofdepthsard environments,ncludiDgheNorth Seaandhydrothermalverrts. hework will beexpanddn the ttu.e to samplemarile microbesrom more han1,000ocaan iteswith evennore typesof environments.he nlemationalcsearchsbeincconductedas partofthe globalCensus f MarineLjfe, a t(n-yearprojecr hatbegan n 2000.The nelvlyrccognizedomplcxi.)- f ocoanbactcria ould ead10a muchgreater enepool for a r-angefsoientific ork.Scientistshave alreadysequenced he eilairegenome or many bacterla. Researchersan cutpiecesiom baoterial )NA and rcplicate t ill manycopies.Though DNA jransf.,thepiccescan


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be insertedn bacterial ells-The cells with the new DNA may hen start o mnkenewproteinstbey wereunablec' nla}e preriously.Thus,bacteria an be genetically llgineeredo makeawhole argeofpr.alucas d to develop ew unctiots.Genetic ngineeringasopenedP anew$ orld of biolos anda rrernendousppo.tlmifyo explore acteria ndothermicloorgansms ndto benefia um"ff+ ft.tm the resultingknowledge.Bacterialcells suchas ,. coli atewidely usedin labo.arori6 6 fecrories o producecommerciallyor medically importantproteins hrough heuseof geFtic nginering r recombinantDNA technologiesResdEh,erst lie US departrnentof energy'sArgome National laboratory havefound a new$a] to snrdy ndividual iving bacterialcells. The scientistused high X-ray fluorescencemerlqrementsor mappingand chemicalanalyses f single ree floating,or planktonic nd$rfac-adheredcells or biofilms of Pseudomonasluorescence.This techniquemeasure hconcentrationf hexavalent hromiumwhich help use o distinguishiving bactrial ell fromdeadcell. Different DNA fingerprintingechniquesave been successfully pplied or theidentification nd taxonomic lassification f the bacteria. 65 rDNA sequences onitor hephysiologioalctivityofmicrobialcellsandsewe n th dentification flactic acidbacteria ndBifidobacteria.65 RNAprobing ndAFLP echniquereused or the dentificationthe gram-positive bacteria that have low G+C content eg.Lactobacillus, Leuconostoc,Enterococccus.RAPD technique s used or the chmacterizatiorof Bifdobacteria includittg B. adolescentis, .hildun. B. brcve.B. inlanti, andB. longun.

microb bacteria

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