earticle

영어

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/gglucose (with a maximum of 15.7 g/Lculture after 48 h) and 0.21 g/gcrude glycerol (with a maximum of 6.9 g/Lculture 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 gmeso-2,3-BDO/gacetoin).