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Updated: Jul 6, 2026

Light-Controlled Fermentations for Microbial Chemical and Protein Production
Published on: March 22, 2022
An effective and simplified pH-stat control strategy for the industrial fermentation of vitamin B(12) by Pseudomonas
Kun-Tai Li1, Dong-Hong Liu, Ju Chu
1State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
Abstract:
In order to improve the productivity of vitamin B(12) by Pseudomonas denitrificans carried out in a 120-m(3) fermenter, the effect of pH on vitamin B(12) 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 B(12). 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 B(12) production was achieved. Accordingly, an effective and simplified pH-stat control strategy was established for the fermentation of vitamin B(12) in a 120-m(3) 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 microg/mL of vitamin B(12) was achieved.
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