大肠杆菌^(60)Co诱变育种及其发酵生产聚唾液酸条件

The Breeding of Escherichia coli^(60)Co Mutagensis Strains and the Conditions on the Production of Polysialic Acid

对产聚唾液酸菌株大肠杆菌WX J11进行6 0 Co诱变 ,筛选出高产突变株WX J4 ,其聚唾液酸产量可达 10 0 1mg/L ,通过优化发酵条件即在 2 50mL的摇瓶中 ,2 50r/min转速下 ,37℃恒温培养 6 5h ,起始 pH值为 7.8,装液量为 4 0mL ,使聚唾液酸的产量提高到 150 0mg/L .聚唾液酸在菌体生长停止后释放到培养基中 ,动力学上表现为次级代谢产物 .此外 ,还对聚唾液酸的提取、水解和唾液酸的纯化作了初步研究 .

The feasibility of 60 Co mutagenesis for increasing polysialic acid production was studied on Escherichia coli WX J11 strain. A polysialic acid overproducing mutant (WX J4) was obtained. The polysialic acid content of the mutant was 1 500 mg/L by optimizing the physical conditions, when the culture was incubated at 37 ℃ for 65 h in 250 mL shaking flasks at 250 r/min, pH 7.8 and operated volume 40 mL. The release of polysialic acid into the broth started when growth stopped, showing typical secondary metabolite in kinetics. The separation and hydrolysis of polysialic acid , purification of sialic acid were preliminarily studied.