重组肺炎克雷伯氏菌转化甘油为聚3-羟基丙酸

Metabolic Engineering of Klebsiella pneumoniae for the Production of Poly (3-Hydroxypropionate) from Glycerol

聚3-羟基丙酸[Poly(3-hydroxypropionate),P3HP]是一种生物可降解及生物相容的新型聚羟基脂肪酸酯。目前已鉴定的生物均不能天然合成P3HP。采用PCR克隆鼠伤寒沙门氏菌的丙醛脱氢酶(Pdu P)基因及罗尔斯通氏菌的聚羟基脂肪酸酯合成酶(Pha C)基因,构建共表达载体,转化肺炎克雷伯氏菌后获得两株重组菌。以甘油为唯一碳源进行摇瓶发酵,pdu P和pha C共用tac启动子的工程菌K.p(p ET-tac-pdu P-pha C)产生0.054 g/L的P3HP,而pdu P和pha C各自独用tac启动子的工程菌K.p(p ET-tac-pdu P-tac-pha C)产生0.091 g/L的P3HP。

Poly （3-hydroxypropionate） （P3HP） represents a novel biodegradable and biocompatible polyhydroxyalkanoate. None of currently identified organisms can naturally synthesize P3HP. Two recombinant Klebsiella pneumoniae strains for the production of P3HP were constructed. The propionaldehyde dehydrogenase gene （pduP） from Salmonella enterica serovar typhimurium LT2 and the polyhydroxyalkanoate synthase gene （phaC） from Ralstonia eutropha H16 were cloned by PCR and cloned into vectors. Transformation of vectors into competent K. pneumoniae cells led to two recombinant strains： K. p （pET-tac-pduP-phaC） , whereby pduP and phaC shared tac promoter, and K. p （pET-tac-pduP-tae-phaC） , whereby pduP and phaC were independently expressed under tac promoter. Using glycerol as the sole carbon source for shake flask fermentation, the strain K. p（pET-tac-pduP-phaC） produced 0. 054 g/L of P3HP, by contrast, the strain K. p （pET-tae-pduP-tac-phaC） produced 0.091 g/L of P3HP.