摘要
为了提高外源L-谷氨酸依赖性菌株枯草芽孢杆菌HB-1产γ-聚谷氨酸(γ-PGA)的能力,采用添加氧载体和前体L-谷氨酸的策略,研究其对菌体生长和γ-PGA产量的影响。摇瓶单因素结果表明,最佳氧载体为聚二甲氧基硅烷(PDMS),在原始培养基中添加体积分数为10%的PDMS,菌体OD600提高了3~5倍;前体L-谷氨酸的最适添加时间为18 h,最适添加质量浓度为10 g/L。在3 L发酵罐扩大培养后,γ-PGA产量提高到45 g/L;在发酵30 h流加碳源和前体L-谷氨酸,γ-PGA质量浓度达到52 g/L。发酵产物经红外,氨基酸分析仪等证实其为多肽类化合物,相对分子质量高达1000万。
In order to improve the ability of exogenous L-glutamate-dependent strain Bacillus subtilis HB-1 to produceγ-poly glutamic acid(γ-PGA),the study explored the effects of adding oxygen carrier and precursor L-glutamic acid on the cell growth and the yield ofγ-PGA.Based on single factor tests,the optimum oxygen carrier was polydimethoxysilane(PDMS),and the cell density increased 3~5 times after the addition of 10%PDMS(v/v)in the initial fermentation medium;moreover,the optimum addition time of precursor L-glutamic acid was 18 h,and the optimum concentration was 10 g/L.With the optimal conditions,the concentration ofγ-PGA increased to 45 g/L in a 3 L fermenter,and its yield reached 52 g/L by the combination of feeding carbon source and L-glutamic acid in 30 h.The fermentation product was confirmed to be a polypeptide compound by infrared and amino acid analyzers,and the molecular weight ofγ-PGA was up to 10 million dalton.
作者
任东雪
陈鹏程
郑璞
徐志南
卢松
REN Dongxue;CHEN Pengcheng;ZHENG Pu;XU Zhinan;LU Song(School of Biotechnology,Jiangnan University,Wuxi 214122,China;College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China;Inner Mongolia Fufeng Biotechnology Co.,Ltd.,Hohhot 010030,China)
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2020年第6期84-92,共9页
Journal of Food Science and Biotechnology
基金
国家“十二五”科技支撑计划项目(2015BAD15B04)
国家自然科学基金青年基金项目(21604032)。
