摘要
γ-聚谷氨酸(γ-polyglutamic acid,γ-PGA)是一种应用于食品、农业、医药等领域的生物聚合物。在不补料发酵γ-PGA过程中,存在因培养基中碳源、氮源不足导致菌体生长发育和γ-PGA合成受限的情况。为实现γ-PGA高产,采用分批补料发酵方式补充菌体生长代谢所需的碳源和氮源,在5 L发酵罐中进行γ-PGA分批补料发酵优化,并在200 L发酵罐进行放大验证。结果表明:当培养基中葡萄糖含量低于5 g/L、氨氮浓度低于0.5 g/L时开始流加补料,持续补料12 h将培养基中葡萄糖浓度维持在5 g/L~15 g/L,氨氮浓度维持在0.5 g/L~1.0 g/L。与不补料发酵相比,这一优化使得菌种指数生长期延长了6 h,生物量(OD_(660))达到了0.62,提升了39.01%,谷氨酸含量降至16 g/L,谷氨酸利用率提升了38.47%,γ-PGA生产强度和产量分别为15.69 g/(L·d)、(47.09±0.82)g/L,均提高了38.45%,为γ-PGA工业化生产提供了技术支撑。
γ-Polyglutamic acid(γ-PGA)is a type of biopolymer used in food,agriculture,and medicine.In the batch fermentation without feeding process ofγ-PGA,the growth and development of the bacteria and the synthesis ofγ-PGA were restricted by insufficient carbon and nitrogen sources in the medium.To obtain a high yield ofγ-PGA,the fed-batch fermentation method was used to supplement the carbon and nitrogen sources required for bacterial growth and metabolism.γ-PGA fed-batch fermentation was optimized in a 5 L fermenter,with amplification in a 200 L fermenter.The experimental results showed that when the glucose and ammonia nitrogen concentrations in the medium were lower than 5 g/L and 0.5 g/L,respectively,the feed was started;the glucose and ammonia nitrogen concentrations were maintained at 5 g/L-15 g/L and 0.5 g/L-1.0 g/L,respectively,for 12 h.Compared with conventional batch fermentation,this optimized method extended the exponential growth period by 6 h,and the biomass(OD_(660))reached 0.62(39.01%increase vs.control).The glutamate level was reduced to 16 g/L,and the glutamate utilization rate was increased by 48.38%.The productivity and yield ofγ-PGA were 15.69 g/(L·d)and(47.09±0.82)g/L,respectively,demonstrating an increase of 38.45%.This study provides useful information for enhancing the industrial production ofγ-PGA.
作者
郭建敏
郭利飞
赵廷彬
李镇江
江源刚
叶莉
唐晓芳
杨志刚
乔长晟
GUO Jian-min;GUO Li-fei;ZHAO Ting-bin;LI Zhen-jiang;JIANG Yuan-gang;YE Li;TANG Xiao-fang;YANG Zhi-gang;QIAO Chang-sheng(College of Biotechnology,Tianjin University of Science&Technology,Tianjin 300457,China;Tianjin Key Laboratory of Industrial Microbiology,Education Ministry Key Laboratory of Industrial Fermentation Microbiology,Tianjin 300457,China;Tianjin Huizhi Biotrans Biotechnology Co.,Ltd.,Tianjin 300457,China;Sichuan Baichuan Jinkai Biological Engineering Co.,Ltd.,Chengdu 610000,Sichuan,China;Sichuan Food Fermentation Industry Research and Design Institute Co.,Ltd.,Chengdu 610000,Sichuan,China)
出处
《食品研究与开发》
CAS
北大核心
2022年第18期191-198,共8页
Food Research and Development
基金
四川省科技计划重点研发项目(2021YFN0135)。
关键词
地衣芽孢杆菌
发酵优化
Γ-聚谷氨酸
分批补料
谷氨酸利用率
葡萄糖
Bacillus licheniformis
optimization of fermentation
γ-polyglutamic acid(γ-PGA)
partial loading
utilization rate of glutamate
glucose
