Antimicrobial activity of the indigenously microbial fermented Fuzhuan brick-tea

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<ul><li><p>hnolo</p><p>References</p><p>Chou, C.C., Lin, L.L., Chung, K.T., 1999. Antimicrobial activity of tea as affected by thedegree of fermentation andmanufacturing season. Int. J. FoodMicrobiol. 48 (2),125130.</p><p>Kawakami, M., Kobayashi, A., Yamanishi, T., Shoujaku, S., 1987. Flavour constituentsof the microbially fermented teas Zhuan-cha and Koku-cha. Nippon Nogeika-gaku Kaishi. J. Agric. Chem. Soc. Jpn. 61 (4), 457465.</p><p>Mo, H.Z., Xu, X.Q., Yan, M.C., Zhu, Y., 2005. Microbiological analysis and antibacterialeffects of the indigenous fermented Puer tea. Agro Food Ind. Hi-Tech. 16 (6),1618.</p><p>Mo, H., Zhu, Y., Chen, Z., 2008.Microbial fermented tea a potential source of naturalS722 Abstracts / Journal of Biotec</p><p>The levels of triglycerides were also lower, due to uptake ofmushroom mycelia.</p><p>As a result of conducted studies it is possible to draw aconclusion that the additives of submerged mycelia of severalbasidiomycetes, tomanage diabetes and leads to essential decreasein a risk of development of arteriosclerosis.</p><p>doi:10.1016/j.jbiotec.2008.07.1716</p><p>VIII1-P-004</p><p>Thermal stability of immobilized lipase fromCandidaantarcticain 1-alcohols and glycerol</p><p>Shuji Adachi , Takashi Kobayashi</p><p>Division of Food Science and Biotechnology, Graduate School of Agri-culture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan</p><p>E-mail address: adachi@kais.kyoto-u.ac.jp (S. Adachi).</p><p>The immobilized lipase from Candida antarctica has been widelyused for the synthesis of esters through condensation or transester-ification. 1-Alcohols and glycerol themselves are one of substratesfor their condensation with a carbonic acid to produce theircorresponding esters. The condensation at a high temperatureaccelerates the reaction rate, but inactivation of the enzymewouldbecomemore significant. In this context, we examined the thermalstability of the immobilized lipase in 1-alcohols with 48 carbonsat 70 C to 115 C and in glycerols with various water contents at80 C to 100 C. The plots of the residual activity versus the incu-bation time on a semi-logarithmic scale did not give a straight linefor all the tested 1-alcohols and glycerol at any temperature, indi-cating that the inactivation did not obey the 1st-order kinetics.Assuming the heterogeneity in the susceptibility of the immobi-lized enzyme to the inactivation, the process was expressed by thefollowing equation (Kawamura et al., 1981):</p><p>CeCe0</p><p>= RT2</p><p>exp</p><p>(R2T2(ln kd ln kd)</p><p>2</p><p>22</p><p>)exp(kdt)d(ln kd)</p><p>(1)</p><p>where Ce is the active enzyme concentration, Ce0 is the initial Ce, Ris the gas constant, T is the absolute temperature, kd is the rate con-stant of thermal inactivation, k is the k corresponding to themeand dvalue of the free energy of activation, G, and is the standarddeviation of G. The inactivation processes of the immobilizedlipase from Candida antarctica in all the tested 1-alcohols and glyc-erols could be well expressed by Eq. (1). The results indicated thatalkyl or glyceryl esters could be synthesized using the enzyme atan abnormally high temperature.</p><p>Acknowledgement</p><p>This studywaspartially supportedbyCooperative for InnovativeTechnologyandAdvancedResearch inEvolutionalArea (CITYAREA)program from the Ministry of Education, Culture, Sports, Scienceand Technology, Japan.</p><p>Reference</p><p>Kawamura, Y., Nakanishi, K., Matsuno, R., 1981. Stability of immobilized -chymotrypsin. Biotechnol. Bioeng. 23, 12191236.</p><p>doi:10.1016/j.jbiotec.2008.07.1718gy 136S (2008) S717S742</p><p>VIII1-P-009</p><p>Antimicrobial activity of the indigenously microbial fermentedFuzhuan brick-tea</p><p>Haizhen Mo1,, Hao Zhang1, Yingqiu Li2, Yang Zhu3</p><p>1 School of Food Science, Henan Institute of Science and Technology,Xinxiang, 453003, China2 College of Food and Bioengineering, Shandong Institute of LightIndustry, Jinan 250353, China3 Food and Bioprocess Engineering Group,Wageningen University, P.O.Box 8129, 6700 EV Wageningen, Netherlands</p><p>E-mail address: hzmo@yahoo.com.cn (H. Mo).</p><p>Antimicrobial activity of extracts from an indigenously fermentedtea, Fuzhuan,was tested in addition to themicrobiological analysis.Microbial counting and identification revealed that Aspergillus spp.,Penicillium spp. and Eurotium spp. were the main microorganismsisolated from the samples of fermentation and Eurotium spp. wasthe dominating fungus responsible for the fermentation. Antibac-terial tests of extracts of fermented tea showed inhibitory effecton several food borne bacteria, including spore forming bacteriaBacillus cereus, Bacillus subtilis, Clostridium perfringens and Clostrid-ium sporogenes. The antibacterial activity increasedwith the courseof the fermentation. This implied that certain metabolites of thefungi growing on tea leaves had the feature of inhibiting certainfood borne spoilage and pathogen microorganisms. These naturalantimicrobial substances have the potential as innovative andmildfood preservatives.</p><p>Keywords: Antimicrobial activity; Aspergillus spp.; Penicillium spp.;Erothium spp.; Fuzhuan brick-tea; Solid-state fermentation; Foodfermentationfood preservatives. Trends Food Sci. Technol. 19 (3), 124130.Schillinger, U., Geisen, R., Holzapfel, W.H., 1996. Potential of antagonistic microor-</p><p>ganisms and bacteriocins for the biological preservation of foods. Trends FoodSci. Technol. 7 (5), 158164.</p><p>Si,W.D., Gong, J., Tsao, R., Kalab,M., Yang, R., Yin, Y.L., 2006. Bioassay-guidedpurifica-tion and identificationof antimicrobial components inChinese green tea extract.J. Chromatogr. A 1125 (2), 204210.</p><p>Xu, X.Q., Mo, H.Z., Yan, M.C., Zhu, Y., 2007. Analysis of characteristic aroma of fungalfermented Fuzhuan brick-tea by gas chromatography/mass spectrophotometry.J. Sci. Food Agric. 87 (8), 15021504.</p><p>doi:10.1016/j.jbiotec.2008.07.1719</p><p>dx.doi.org/10.1016/j.jbiotec.2008.07.1716mailto:adachi@kais.kyoto-u.ac.jpdx.doi.org/10.1016/j.jbiotec.2008.07.1718mailto:hzmo@yahoo.com.cndx.doi.org/10.1016/j.jbiotec.2008.07.1719</p></li></ul>

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