pgpA和tdcG基因的敲除对大肠杆菌磷脂酰丝氨酸合成的影响

Effect of Gene pgpA and tdcG Knock-off on the Phosphatidylserine Biosynthesis in Escherichia coli

磷脂酰丝氨酸具有改善大脑的认知和记忆的功能,是医药和食品行业重要的原料.为进一步提高大肠杆菌(Escherichia coli)中磷脂酰丝氨酸含量,利用Red重组系统,以可积累磷脂酰丝氨酸的E.coli K12(△sda A△sda B△pgp B)为出发菌株,敲除pgp A和tdc G基因,切断与磷脂酰丝氨酸合成相关的L-丝氨酸和磷脂酰甘油磷酸的分解代谢途径.摇瓶发酵后的检测结果表明,重组菌株E.coli K12(△sda A△sda B△pgp A△pgp B△tdc G)中磷脂酰丝氨酸占菌体总磷脂的比例为2.5%,较出发菌株(1%)提高了1.5倍.

Phosphatidylserine（PS）is an important active ingredient for medicine and food industry which could improve the cognitive ability and memory. In order to improve the content of PS in Escherichia coli, the Red recombinant system was used for deleting the gene pgpA and tdcG in E. coli K12（sdaA sdaB pgpB）which can accumulate PS to block the L-serine degradation and cutting off the phosphatidylglycerophosphate catabolic pathway. After fermentation,the results showed that the total PS phospholipids synthesized by the mutant strain E. coli K12（pgpApgpBsdaAsdaBtdcG）was 2.5%which was 1.5 times higher than that in the starting strain（1%）.