Research and Development Center, GS Caltex Corporation, 104-4 Munji-dong, Yuseong-gu, Daejeon 305-380, Republic of Korea.
J Biosci Bioeng. 2013 Aug;116(2):186-92. doi: 10.1016/j.jbiosc.2013.02.021. Epub 2013 May 1.
Fermentative 2,3-butanediol (2,3-BD) production has been receiving increasing interest for its potential as a platform chemical intended for the production of synthetic rubbers, plastics, and solvents. In this study, Klebsiella oxytoca GSC 12206, a 2,3-BD native hyper-producing and nonpathogenic bacterium, was isolated from a cattle farm. Since this isolate produced a significant amount of lactic acid along with 2,3-BD, its mutant deficient in lactic acid formation was constructed by disrupting the ldhA gene which encodes lactate dehydrogenase. The ldhA gene was deleted precisely by using the pKGS plasmid. When compared to the wild-type strain, the mutant deleted with the ldhA gene in glucose fermentation resulted in an increase of 54%, 13%, 60%, and 78% of 2,3-BD titer, productivity, yield, and selectivity, respectively. A fed-batch fermentation by this mutant with intermittent glucose feeding produced 115 g/L of 2,3-BD with an yield and productivity of 0.41 g 2,3-BD per g glucose and 2.27 g/L h, respectively, indicating the usefulness for the industrial production of 2,3-BD.
发酵 2,3-丁二醇（2,3-BD）因其作为平台化学品的潜力而受到越来越多的关注，可用于生产合成橡胶、塑料和溶剂。在这项研究中，从一个奶牛场中分离到一株 2,3-BD 原生高产且非致病性的肠杆菌属（Klebsiella）菌株 GSC 12206。由于该分离株在生产 2,3-BD 的同时会产生大量的乳酸，因此通过敲除编码乳酸脱氢酶的 ldhA 基因构建了其突变株，该基因缺失的突变株无法形成乳酸。使用 pKGS 质粒精确地敲除了 ldhA 基因。与野生型菌株相比，在葡萄糖发酵中敲除 ldhA 基因的突变株的 2,3-BD 产量、生产效率、产率和选择性分别提高了 54%、13%、60%和 78%。该突变株在间歇葡萄糖补料的分批发酵中可生产 115 g/L 的 2,3-BD，产率和生产效率分别为 0.41 g 2,3-BD/g 葡萄糖和 2.27 g/L·h，表明该突变株可用于 2,3-BD 的工业化生产。
