大肠杆菌Lin43利用甘油产丙酮醇⎯通过敲除gloB基因改善丙酮醛耐受性

摘要

采用重组大肠杆菌 Lin 43利用甘油产丙酮醇。为了改善菌株对丙酮醛的耐受性，采取敲除 glo B基因而不是gloA 基因以阻断丙酮醛的脱毒途径。实验结果表明，菌株 Lin43ΔgloB 对丙酮醛的耐受性要明显优于 Lin43ΔgloA。在含20 g⋅L-1的甘油磷酸盐缓冲液中，通过26 h 静息细胞转化，菌株 Lin43∆gloB pCA24N-yqhE 丙酮醇产量达到2.30 g⋅L-1，并能耐受3.5 mmol⋅L-1的丙酮醛。同时 Lin43∆gloB pCA24N-yqhE 实现重复发酵，第二轮发酵的产量可达1.53 g⋅L-1，丙酮醇的得率与第一轮相同。%Gene gloB instead of gloA in the strain of Escherichia coli Lin43 was knocked out to disrupt the detoxification pathway of methylglyoxal. The results show that the tolerability of strain Lin43ΔgloB is much better than that of the strain Lin43 ΔgloA. After resting the cells of strain Lin43 ΔgloB pCA24N-yqhE in the phosphate buffer with 20 g⋅L-1of glycerol, it produces 2.30 g⋅L-1 of acetol in 26 h and can resist 3.5 mmol⋅L-1 methylglyoxal. Moreover, 1.53 g⋅L-1 acetol can be produced with strain Lin43 ΔgloB pCA24N-yqhE in the second round production, which has similar yield as that of the first round.