S178 Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576

Fig. 2. (a) profile of ethanol and (b) profile of the products of fermentation. TheGlycerol’s concentrations are: ( ) 20 g/L, ( ) 15 g/L, (�) 10 g/L, ( ) 1 g/L.

Results: In the Fig. 1 we have the consumption of glycerol andbiomass production and in the Fig. 2 we have the production ofethanol and acetic acid.

Through graphics of fermentation can be seen that with 10 g/Lof glycerol was obtained the best production of ethanol, about0.78 g/L, but in other fermentations the values of production werebelow 0.4 g/L of ethanol.

Discussion: Through this work we could examine the influenceof the concentration of glycerol in the fermentation media. Thisstudy showed that it is possible to use crude glycerol to produceethanol and that the best concentration was using 10 g/L of crudeglycerol.

doi:10.1016/j.jbiotec.2010.08.463

[P-B.111]

Gene cloning and expression of thermostable laccase from Ther-mus thermophilus HJ6

Min-Ho Seo, Eon-Seok Lee, Sung-Jong Jeon ∗

Dong-Eui University, Democratic People’s Republic of KoreaKeywords: Laccase; Thermus; Thermostability; Purification; Char-acterization

The gene encoding the laccase was cloned and sequencedfrom Thermus thermophilus HJ6. The open reading frame (ORF)of the laccase gene was composed of 1,389 nucleotides andencoded a protein (462 amino acids) with a predicted molec-ular weight of 51.1 kDa. The deduced amino acid sequenceof laccase showed 99% identities to the Thermus thermophilusHB27. Laccase gene was expressed in Escherichia coli cells,and the recombinant protein was purified to homogeneity,which displayed a blue color typical of laccases and oxidizedcanonical laccase substrates such as guaiacol and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonate). The optimal temperatureand pH for laccase activity were found to be 90 ◦C and 5.5,respectively.

doi:10.1016/j.jbiotec.2010.08.464

[P-B.112]

Application of novel solid acid and base catalysts in biodieselsynthesis

Zhi-Long Xiu ∗, Feng Guo

Dalian university of technology, ChinaKeywords: Biodiesel; Biomass-derived carbonaceous solid acid;Calcined sodium silicate; SOLID catalsyt

As replacement of fossil diesel, biodiesel has gained significantattention in recent years. Low-cost lipids are fostered to be usedas feedstock to reduce the material cost. However, soaps are usu-ally produced during homogeneous catalytic process due to smallamounts of water or free fatty acids existed in oil, resulting in thecatalyst deactivation and productivity reduction. In this study, thebiomass-derived carbonaceous solid acid and calcined sodium sil-icate have been developed to achieve a green process of biodieselproduction.

Lignin-derived carbonaceous catalyst was developed by directsulphonation of residue from hull of Xanthoceras sorbifolia Bungehydrolyzed by cellulase after pretreatment of diluted sulfuric acid.Acidified oil from soybean soapstock was chosen as materials andesterified to produce biodiesel. Under the optimal esterificationconditions, the acidic value was reduced from 112.4 mg KOH/g to3.12 mg KOH/g.

Calcined sodium silicate was directly used to catalyze the trans-esterification of crude cottonseed oil containing 1.28 wt % FFA and2.07 wt % water. The optimum transesterification reaction condi-tions were obtained as following: 2.48 wt % of catalyst amount,7.6:1 methanol/oil of molar ratio, 59 ◦C and 225 r/m of stir-ring speed. Under those conditions, the biodiesel yield can reachto 95.1%. Compared with NaOH and CaO, the transesterificationcatalyzed by calcined sodium silicate has advantages of higher con-version, no soap formation and easy recovery.

A two-step method was proposed to produce biodiesel fromthe bone oil containing above 40 wt % of fatty acid, in which thefirst esterification step was catalyzed by solid acid and the sec-ond transesterification step was catalyzed by solid base. Comparedwith combination of concentrated H2SO4–NaOH or concentratedH2SO4–CaO, the combination of biomass-derived carbonaceouscatalyst with calcined sodium silicate could obtain higher biodieselyield, more simple process of biodiesel preparation and more stablecrude product.

doi:10.1016/j.jbiotec.2010.08.465

[P-B.113]

Bioethanol from cheese whey fermentation usingKluyveromyces marxianus biofilm

Yogesh Joshi 1,2,∗, Massimo Poletto 1,2, Beatrice Senatore 1,2

1 University of Salerno, Italy2 Prodal Scarl, c/o Università di Salerno, ItalyKeywords: Kluyveromyces marxianus biofilm; Cheese whey

Fuel ethanol production by fermentation of cheese wheysolution (lactose) can be a sustainable route for its high volume pro-duction worldwide and environmental pollution problem causeddue to its high BOD(40-50 g.L−1) and COD(60 - 80 g.L−1) demand.Fermentation of cheese whey using free and immobilized yeastsSaccharomyces cerevisiae(Lewandowska et al., 2007), Kluyvromycesfragilis(Gianetto et al.,1986), Candida psudeotropicalis(Ghaly andEl-Taweel,1997), Kluyveromyces marxianus (Ozmihci and Kargi,2007; Zafar et al., 2005) has been reported with technical prob-

Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576 S179

lems like poor substrate (lactose) utilization(in case of S.cerevisiae),substrate (lactose) and product (ethanol) inhibition affectingfinal ethanol concentration (batch) and ethanol productivity(continuous).

Biofilm technology has been extensively applied in wastewatertreatment, but its potential application in bioethanol produc-tion has not been explored. In general, advantages of biofilmsinclude selective substrate and product diffusion due to lay-ered microbial structure, prevention of cell wash out due toEPS (extra polymeric substance) formation, operational stabil-ity due to high resistance to external environment. This latteradvantage is in particular sought in the bioethanol fermentationprocess.

Kluyveromyces marxianus yeast strains has shown excellentethanol tolerance (free and immobilized) and biofilm form-ing ability without any selective preference of support in thecited literature. The present research work involves studyingthe feasibility of anaerobic fermentation of cheese whey usingKluyveromyces marxianus DSMZ 5422 biofilm on particle supportin batch and continuous mode. The first phase of the researchinvolves characterization of Kluyveromyces marxianus DSMZ 5422by fermentation of cheese whey powder solution at different con-centration, pH and inoculum concentration. Natural supports suchas olive pits and artificial supports such as polypropylene chipsare tested for the holding capacity of Kluyveromyces marxianusDSMZ 5422 biofilm. Direct qualitative and indirect quantitativeevaluation of the biofilm formation on the different support iscarried out.

References

Ghaly & El-Taweel (1997) Biomass Bioenergy, 12(6), 461-472.Gianetto, A., Berutti, F., Glick, B., Kempton, A., 1986. Appl.Microbiol.Biotechnol 24,

277–281.Lewandowska, M., Staniszewski, M., Kujawski, W., 2007. J.Food Engg 82, 618–625.Ozmihci, S., Kargi, F., 2007. Lett.Appl.Microbiol 44, 602–606.Zafar, S., Owais, M., Saleemuddin, M., Hussain, S., 2005. J.Food Sci & Tech 40, 597–604.

doi:10.1016/j.jbiotec.2010.08.466

[P-B.114]

Applications of extractive fermentation and hot compressedwater to enhance bioenergy production from food wastes

M.D. Redwood ∗, R. Orozco, A.J. Majewski, L.E. Macaskie

University of Birmingham, United KingdomKeywords: Bioenergy; Extractive fermentation; Hot compressedwater; Food waste

We are at risk of energy poverty. Fossil fuels will last only afew more decades and nuclear installations cannot be built quicklyenough to meet the expected shortfall as demand continues togrow Bockris, 2007. The transition to clean, renewable energy isurgent and will require multiple technologies, including biologicalRedwood et al., 2009.

Anaerobic fermentation is a cornerstone of bioprocessingapplied in the generation of biofuels such as butanol, ethanoland hydrogen. However, fermentation is ultimately limited by itsorganic products. To prolong activity in hydrogen producing E.coli fermentations, we applied extractive fermentation to separateorganic acids in response to pH, controlling pH and organic acidconcentration simultaneously. The duration of biohydrogen pro-duction from glucose was enhanced without sacrificing conversionrate or yield.

UK domestic and food industry biodegradable wastes equateto 24 Mt annually Hogg et al., 2008, potentially providing ∼13%

of our 2020 target (15% renewables by 2020) without consider-ing other organic waste sources, e.g. agriculture. For this study,food wastes were sourced from commercial producers includingcatering kitchens and fruit traders. Simple sugars were sepa-rated by mechanical pressing and washing before treating theinsoluble residue with hot compressed water to liberate furthersimple sugars. Fractions were characterised and tested in vial-scalereactions before progressing to extractive fermentations. Thesetreatments proved effective in generating a sugary feed suitablefor extractive fermentation with E. coli and free of significantinhibitory components. Despite the presence of non-sugar compo-nents in waste-derived feeds the efficiency of extraction remainedhigh.

We conclude that extractive fermentation and hot compressedwater are versatile tools offering noteworthy advantages for theintegrated bioenergy refinery.

References

Bockris, J.O.M., 2007. Int J Hydrogen Energy 32, 153–158.Redwood, M.D., et al., 2009. Rev Environ Sci Biotechnol 8 (2), 149–185.Hogg D., et al., Dealing with Food Waste in the UK. WRAP

http://www.wrap.org.uk/document.rm?id=3603. 2008.

doi:10.1016/j.jbiotec.2010.08.467

[P-B.115]

Production of gaseous or liquid value-added products in bioelec-trochemical systems

M. Villano 1,2,∗, M. Rosenbaum 2, F. Aulenta 1, M. Majone 1, L.T.Angenent 2

1 Sapienza University of Rome, Italy2 Cornell University, United StatesKeywords: Bioelectrochemical systems; Biocathode; Biofuels

Bioelectrochemical systems (BESs) are devices that takeadvantage of the ability of bacteria to engage in extracellularelectron transfer processes with solid-state electrodes. The mostextensively studied BES is the microbial fuel cell (MFC), whichis regarded as an innovative and sustainable technology forwastewater treatment. In a MFC, the electrons released from thebacterial oxidation of waste organic substrates (with an anodeserving as terminal electron acceptor) are exploited for electri-cal power generation. Since the value of electric power is low,fortunately, BES can also generate chemical products, and muchresearch effort is currently being dedicated to the developmentof novel BES concepts in which the oxidation of waste organicsubstrates is coupled to the production of reduced value-addedproducts. Here, we are focusing on the development of efficient(bio)catalytic systems at the cathodes of BESs for the productionof gaseous or liquid biofuels, such as hydrogen, methane, alcohols,and hydrocarbons. We found that biocathodes, teaming with livinghydrogenase-containing microorganisms, are capable of catalysinghydrogen or methane production using graphite electrodes asdirect electron donors for H+ or CO2 reduction, respectively. Inparallel, we are also investigating the use of metal-based catalystson cathodes to convert CO2 into liquid fuels, such as alcoholsand hydrocarbons. The obtained results pinpoint the remarkablepotential of BES for extracting value from wastewater.

doi:10.1016/j.jbiotec.2010.08.468