摘要
为建立费氏丙酸杆菌的半连续耦合发酵工艺,克服DMB对维生素B_(12)连续发酵的不利影响,考察了费氏丙酸杆菌菌体细胞离位转化合成维生素B_(12)的可行性,优化了其离位转化工艺,确定了最佳的转化时机、转化体系及DMB添加方式,具体如下:当发酵进行至84 h时,将发酵液离心,收集菌体,然后用离心上清液重悬菌体,配成5倍浓度的菌液,加入终浓度为4.5 mg/L的DMB,于30℃条件下转化48 h,维生素B_(12)的产量达到108.06 mg/L,转化效率为2.26 mg/(Lh)。
The semi-continuous coupling fermentation process can significantly improve the economical efficiency of Propionibacterium freudenreichii.In order to avoid the negative effect of DMB addition on Propionibacterium freudenreichii semi-continuous fermentation,the feasibility of synthesis of vitamin B12 by ex-situ cell transformation is investigated.Also,the ex-situ cell transformation process is optimized from the aspects of cell seperation time,transformation system and DMB addition mode.The details are as follows：when the fermentation process is carried out for 84 h,cells are removed from the fermentation broth by centrifugation.The supernatant is used to resuspended the cells and a 5 times concentration suspension is obtained.Then a final concentration of 4.5 mg/L DMB is added to synthesis vitamin B_（12） for 48 h at 30 ℃.The Vitamin B_（12） yield can reached 108.06 mg/L,with a conversion efficiency of 2.26 mg/（Lh）.
出处
《中国生物工程杂志》
CAS
CSCD
北大核心
2016年第4期104-109,共6页
China Biotechnology
基金
国家重点基础研究发展计划(973)基金(2013CB733604)资助项目
关键词
费氏丙酸杆菌
维生素B12
离位转化
Vitamin B_（12）
Propionibacterium freudenreichii
Ex-situ cell transformation
