초록
<P>meso-2,3-Butanediol (meso-2,3-BDO) is essential for the synthesis of various economically valuable biosynthetic products; however, the production of meso-2,3-BDO from expensive carbon sources is an obstacle for industrial applications. In this study, genes involved in the synthesis of 2,3-BDO in Klebsiella pneumoniae were identified and used to genetically modify Escherichia coli for meso-2,3-BDO production. Two 2,3-BDO biosynthesis genes-budA, encoding acetolactate, and meso-budC, encoding meso-SADH-from K. pneumoniae were cloned into the pUC18 plasmid and introduced into E. coli. In 2??l batch culture, the SGSB03 E. coli strain yielded meso-2,3-BDO at 0.31??g/g(glucose) (with a maximum of 15.7??g/l(culture) after 48??h) and 0.21??g/g(crude glycerol) (with a maximum of 6.9??g/l(culture) after 48??h). Batch cultures were grown under optimized conditions (aerobic, 6% carbon source, 37??°C, and initial pH 7). To find the optimal culture conditions for meso-2,3-BDO production, we evaluated the enzyme activity of meso-SADH and the whole cell conversion yield (meso-2,3-BDO/acetoin) of the E. coli SGSB02, which contains pSB02. meso-SADH showed high enzyme activity at 30-37??°C and pH 7 (30.5-41.5 U/mg of protein), and the conversion yield of SGSB02 E. coli was highest at 37-42??°C and a pH of 7 (0.25-0.28 g( meso-2,3-BDO)/g(acetoin)).</P>