Project description:An aminotransferase ?-TAEn was identified from Enhydrobacter aerosaccus. The ?-TAEn was successfully expressed in Escherichia coli and the obtained enzyme showed activity toward ?-phenylalanine (?-phe) at optimal conditions. For optically pure (R)-?-phe, 50% yield was observed by kinetic resolution of racemic amino with pyruvate as the amino acceptor. To obtain (S)-?-phe, the lipase/?-TAEn catalytic system was adopted. The ?-TAEn showed strict stereoselectivity to the amino donor. The formation of (S)-?-phe was observed using 3-aminobutyric acid as the amino donor, and (S)-?-phe was obtained by asymmetric synthesis with a yield of 82%.
Project description:Cellulase finds use in saccharification of lignocellulosic agroresidues to fermentable sugars which can be used for production of commercially important metabolites. This study reports endoglucanase (CMCase) production by Enhydrobacter sp. ACCA2. The CMCase activity of the strain ACCA2 was successively improved by optimization of range of physical and nutritional parameter in a set of non-statistical and statistical experiments. Initial non-statistical selection of carbon source, incubation time, temperature and pH resulted in 1.07 fold increase of CMCase activity. In a subsequent statistical method, response surface methodology, optimization of medium components such as carboxymethylcellulose, peptone, NaCl, MgSO4, K2HPO4, and (NH4)2SO4 yielded further increase up to 2.39 fold CMCase activity. The cellulolytic potential was evaluated in biomass saccharification with different plant materials and the results revealed that the enzyme produced by strain may have significant commercial values for industrial saccharification process. Moreover, this is the first report of cellulase production by an Enhydrobacter spp.