直接发酵法生产L-丝氨酸高产菌株的选育  

Breeding of High-Yield L-Serine Producing Strains Which Can Ferment Sugar Directly

作　　者：徐国强[1,2] 窦文芳[1] 许泓瑜[1] 张晓梅[1,2] 

机构地区：[1]江南大学药学院,江苏无锡214122 [2]江南大学粮食发酵工艺与技术国家工程实验室,江苏无锡214122

出　　处：《食品与生物技术学报》2014年第11期1191-1195,共5页Journal of Food Science and Biotechnology

基　　金：国家863计划项目(2012AA022102);广东省教育厅项目(2012B091000083)

摘　　要：为了解除高浓度L-丝氨酸对3-磷酸甘油酸脱氢酶的反馈抑制,进一步提高L-丝氨酸的产量,以一株能直接利用糖质原料发酵生产L-丝氨酸的谷氨酸棒杆菌SYPS-062-36为出发菌,经硫酸二乙酯逐级诱变处理,在D-丝氨酸抗性梯度平板上挑取正突变株,获得一株遗传性能稳定的高产菌株SYPS-062-33a-18,其可积累L-丝氨酸(11.0±0.25)g/L,较出发菌L-丝氨酸产量(6.65±0.23)g/L提高了65.4%。说明本研究不仅以D-丝氨酸作为抗性平板筛选得到高产L-丝氨酸的突变株,而且为下一步进行反向代谢工程的研究提供了良好的实验材料。C.glutamicum SYPS-062-36 could produce L-serine from sugar directly,in order to further improve L-serine production via removing the feedback inhibition of PGDH caused by high concentration of L-serine,a mutant strain C.glutamicum SYPS-062-33a-18 was obtained by DES treatment of C.glutamicum SYPS-062-36 for two rounds and selecting positive mutant in the plate containing D-serine.The genetic stable mutant strain could accumulate 11.0 ± 0.25 g/L of L-serine,with an increase of 65.4％ compared with the parental strain.These results suggested that L-serine overproduced strain can be obtained by using random mutagenesis and directed selection with D-serine as the analog,and also provide a valuable basis for further improving L-serine production with inverse metabolic engineering.

关 键 词：直接发酵法 L-丝氨酸 高产菌株 诱变育种 谷氨酸棒杆菌 

分 类 号：TQ922[轻工技术与工程—发酵工程]