The Method And Condition Optimization Of Production Indigoidine With L-glutamine Strain

First,through cloning、over-expression in E coli and protein purification,we obtained pure BPSA protein.Kinetic analysis of BPSA indicate that its Km value.Based on the fact that BPSA can produce blue pigment indigoidine using L-glutamine as substrate,we successfully develop a high throughput method for screening L-glutamine over-producing strain.The results are as follows:Kinetic analysis of BPSA indicate that its Km value is 0.79±0.667mM and Kcat value is 5.658mM.When the concentration of L-glutamine in fermentation broth was between 0.2mM and 5mM,the content of L-glutamine could be detected by this method.In this study,via cloning and co-expression of bpsA and sfp gene,we demonstrated indigoidine production in Corynebacterium glutamicum for the first time.We then optimized fermentation conditions by changing L-glutamine concentration((0、0.73、4.38.11.68)g/L).IPTG concentrations((0.1、0.2、0.4、0.8、1.5、2)mM)、induction time(48h、72h)and temperatures(18 ℃、25 ℃、30℃).The results indicate that the indigoidine production is 1.75g/L when IPTG concentration is 0.8mM and cell was induced at 18 ℃ for 48hours.