ε-聚赖氨酸产生菌的复合诱变筛选及其发酵培养基优化

Breeding of ε-poly-L-lysine producing strain with combined mutation and the optimization of its fermentation medium

以白色链霉菌FQ-9为出发菌株,首次利用(甘氨酸+L-赖氨酸+磺胺胍)复合抗性,进行"紫外-氯化锂"复合诱变,筛选出一株ε-PL产量达(0.668±0.0045)g/L的突变菌株FQC-23,产量提高了15.37%,且其遗传性稳定。然后在单因素实验的基础上,应用响应面分析方法,对其发酵培养基进行优化,最终确定最佳培养基为(g/L):葡萄糖46.1、酵母粉13.0、(NH4)2SO45.9、Mg SO4·7H2O 0.5、K2HPO40.8、KH2PO41.36、Fe SO4·7H2O 0.03、Zn SO4·7H2O 0.04,在此条件下,FQC-23的ε-PL产量达(1.090±0.0041)g/L,比出发菌株的产量提高了87.56%。

Using Streptomyces albulus FQ-9 as the initial strain mutated by UV combined with Li Cl,and using glycine ＋sulfaguanidine（SG） ＋L-lysine as selective markers. Then,a ε-PL-producing strain,Streptomyces albulus FQC-23 of the yield improved to（0.668±0.0045） g/L was screened,which was 15.37% higher than that of FQ-9. Moreover,based on single factor experiment,the fermentation medium of ε-PL producing strain FQC-23 were optimized by response surface methodology,and finally determined the optimal fermentation medium as follows（g/L）：glucose 46.1,yeast powder 13.0,（NH4）2SO45.9,Mg SO4·7H2O 0.5,K2HPO40.8,KH2PO41.36,Fe SO4·7H2O 0.03,Zn SO4·7H2O 0.04. Under the optimized medium,the yield of ε-PL reached（1.090±0.0041） g/L and increased by 87.56% compared with the previous condition.