Improved propionic acid and 5,6-dimethylbenzimidazole control strategy for vitamin B12 fermentation by Propionibacterium freudenreichii
Improved propionic acid and 5,6-dimethylbenzimidazole control strategy for vitamin B12 fermentation by Propionibacterium freudenreichii
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费氏丙酸杆菌发酵维生素 B12 的改进丙酸和 5,6-二甲基苯并咪唑控制策略
DOI：
10.1016/j.jbiotec.2014.11.019
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发表时间：
2015-01-10
影响因子：
4.1
通讯作者：
Wang, Yunshan
中科院分区：
文献类型：
--
作者：
Wang, Peng;Zhang, Zhiwei;Wang, Yunshan
为了提高维生素B12的厌氧发酵效率，采用弗氏丙酸杆菌优化发酵工艺，研究了副产物丙酸和前体5，6-二甲基苯并咪唑(DMB)对维生素B12生物合成的影响。副产物抑制实验表明，发酵液中丙酸浓度早期控制在10~20g/L以下，后期控制在20~30g/L以下，可有效促进维生素B12的生物合成。分批发酵表明，胞内中间体生物合成存在反馈抑制现象。此外，前体DMB的加入取决于维生素B12中间体的发酵水平。采用膨胀床吸附生物反应器，以丙酸和DMB为对照，可获得较高的维生素B12浓度(58.8 mg/L)和产量(0.37 mg/g)。连续5批发酵后，维生素B12的最适生产浓度和产量分别为59.5 mg/L h和0.59 mg/L h。(C)2014爱思唯尔B.V.保留所有权利。
An efficient fermentation-strengthening approach was developed to improve the anaerobic production of vitamin B12 by cultivation process optimization with Propionibacterium freudenreichit The effects of the byproduct propionic acid and the precursor 5,6-dimethylbenzimidazole (DMB) on vitamin B12 biosynthesis were investigated. Byproduct inhibition experiments showed that maintaining propionic acid concentration in broth below 10-20 g/L in the early stage and 20-30 g/L in the late stage can efficiently improve vitamin B12 biosynthesis. Batch fermentation indicated the occurrence of feed-back inhibition in intracellular intermediate biosynthesis. In addition, the incorporation of the precursor DMB depended on the fermentation level of the vitamin B12 intermediate. High vitamin B12 concentration (58.8 mg/L) and production (0.37 mg/g) were obtained with an expanded bed adsorption bioreactor by using the propionic acid and DMB control method. The optimum concentration and production of 59.5 and 0.59 mg/L h for vitamin B12 production were respectively achieved after five continuous batches. (C) 2014 Elsevier B.V. All rights reserved.