过表达氨基葡萄糖脱氨酶对大肠杆菌氨基葡萄糖合成及中心碳代谢的影响

摘要

The effects on glucosamine synthesis and central carbon metabolism in E.coli by overexpression glucosamine deaminase were investigated.The results showed that overexpression glucosamine deaminase nagB could improved the content of glucosamine by two times of that of Rosetta,under the conditions of 36 g/L glucose,pH 9.0,after 24 h fermentation.The content of pyruvate was 1.48 times,acetic acid was 1.74 times,citric acid was 2.99 times,α-ketoglutaric acid was 2.73 times of that of Rosetta,respectirely.Lactic acid content of recombinant was 2.53 g/L.Lactic acid content of the original bacteria was not detected.These preliminary findings showed that,overexpression of the glucosamine deaminase promoted the accumulation of glucosamine in E.coli,overexpression of the glucosamine deaminase also made the accumulation of pyruvate,acetic acid and lactic acid.Overexpression of the glucosamine deaminase has great impact on the TCA cycle,high level of the citric acid and α-ketoglutaric acid were detected.%考察过表达氨基葡萄糖脱氨酶对氨基葡萄糖合成及大肠杆菌(Escherichia coli中心碳代谢的影响.实验结果表明:过表达氨基葡萄糖脱氨酶使得在36 g/L葡萄糖,pH为9.0的发酵条件下,发酵24 h后,重组菌发酵液中氨基葡萄糖、丙酮酸和乙酸的量分别是对照菌Rosetta的2.1、1.48和1.74倍;而乳酸的量为2.53 g/L,对照菌Rosetta发酵液中的乳酸含量未检测到,重组菌发酵液中柠檬酸及α-酮戊二酸的含量分别是Rosetta的2.99和2.73倍.