三株聚谷氨酸高产菌的鉴定及产物特性  

Identification of three high-productive strains of poly(γ-glutamic acid) and characterization of their products

作　　者：肖磊[1] 李娟[1] 杨燕[2] 刘敏[1] 张利[1] 黄静[1] 吴自荣[1] 

机构地区：[1]华东师范大学生命科学学院,上海200241 [2]上海市食品药品检验所,上海201203

出　　处：《工业微生物》2013年第4期9-15,共7页Industrial Microbiology

基　　金：国家863项目(2009AA03Z429);国家自然科学基金项目(31170920)

摘　　要：根据形态学特征、16S rDNA保守序列的测定、核糖体分型结果把实验室筛选分离的三株产聚谷氨酸菌(编号分别为CC、DL、TW)分类鉴定为枯草芽孢杆菌。三株产聚谷氨酸菌的发酵周期、γ-聚谷氨酸(γ-PGA)产量、分子量及结构均存在一定差异,菌株CC、DL和TW的发酵周期分别为48 h、72 h和60 h,γ-PGA最高产量分别为27.6 g/L、31.5 g/L和27.0 g/L,平均分子量分别为814 kDa、702 kDa和924 kDa;菌株CC发酵周期最短,菌株DL的γ-PGA产量最高,菌株TW的γ-PGA分子量最大。三株产聚谷氨酸菌生产的γ-PGA均为D-L-混合型,但比例不同,来源于菌株CC的γ-PGA含有较高比例的L-谷氨酸。三者生产的γ-PGA均有较高絮凝活性,其中来源于菌株DL的γ-PGA絮凝活性可达到75.9%。三株菌发酵产γ-PGA的性质各有不同,为工业上不同要求的聚谷氨酸应用提供了新的高产发酵菌株,值得深入开发研究。Three novel γ-PGA producing strains（ strain CC, DL and TW） were isolated and identified as Bacillus subtilis based on colony morphology, micromorphology and genetic methods. According to the fermentation experiments, the γ- PGA yield of strain CC reached 27.6 g/L with average molecular weight of 814 kDa after 48 h fermentation; the γ-PGA yield of strain DL reached 31.5 g/L with average molecular weight of 702 kDa after 72 h fermentation ; the γ-PGA yield of strain TW reached 27.0 g/L with average molecular weight of 924 kDa after 60 h fermentation. The γ-PGA harvested from the three strains were all D-L-glutamic but of different proportions. More L-glutamic acid were contained in the γ-PGA from strain CC. High flocculating rate were observed in all the three strains and the flocculating activity of the γ-PGA from strain DL was 75.9%. The three strains with distinct characteristics could satisfy various industrial requirements, hence worthy of further industrial research.

关 键 词：Γ-聚谷氨酸 菌种鉴定 絮凝 

分 类 号：TQ922.1[轻工技术与工程—发酵工程]