文献类型：期刊文献

英文题名：An effective and simplified pH-stat control strategy for the industrial fermentation of vitamin B12 by Pseudomonas denitrificans

作者：Li, Kun-Tai[1]; Liu, Dong-Hong[1]; Chu, Ju[1]; Wang, Yong-Hong[1]; Zhuang, Ying-Ping[1]; Zhang, Si-Liang[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China

年份：2008

卷号：31

期号：6

起止页码：605

外文期刊名：Bioprocess and Biosystems Engineering

收录：EI(收录号：20090711901917)

语种：英文

外文关键词：Bacteria - Biochemistry - Biosynthesis - Fermentation - Betaines - Chlorine compounds

摘要：In order to improve the productivity of vitamin B12 by Pseudomonas denitrificans carried out in a 120-m3 fermenter, the effect of pH on vitamin B12 biosynthesis was investigated. Results obtained from shake flask experiments showed that the feeding of carbon source (beet molasses or glucose) and methyl-group donor (betaine or choline chloride) significantly influenced the pH and the biosynthesis of vitamin B12. In contrast to beet molasses or choline chloride, using glucose as a feed medium and betaine as a methyl-group donor, pH could be maintained at a stable range. As a result, higher vitamin B12 production was achieved. Accordingly, an effective and simplified pH-stat control strategy was established for the fermentation of vitamin B12 in a 120-m3 industrial fermenter. When the new pH control strategy was applied, pH was stably kept in the range of 7.15-7.30 during fermentation. Thus, 214.3 μg/mL of vitamin B12 was achieved. ? 2008 Springer-Verlag.