title: An effective and simplified pH-stat control strategy for the industrial fermentation of vitamin B(12) by Pseudomonas denitrificans.
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.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Kun-Tai
authors.initials: KT
authors.lastname: Li
authors.forename: Dong-Hong
authors.initials: DH
authors.lastname: Liu
authors.forename: Ju
authors.initials: J
authors.lastname: Chu
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Ying-Ping
authors.initials: YP
authors.lastname: Zhuang
authors.forename: Si-Liang
authors.initials: SL
authors.lastname: Zhang
mesh_terms: D001622:Betaine / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods; D002794:Choline / Q000737:chemistry; D003470:Culture Media; D005285:Fermentation; D005947:Glucose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D008828:Microbiological Techniques; D008965:Molasses; D010100:Oxygen / Q000737:chemistry; D011549:Pseudomonas / Q000378:metabolism*; D013997:Time Factors; D014805:Vitamin B 12 / Q000737:chemistry*
chemical_list: D003470:Culture Media; D001622:Betaine; D005947:Glucose; D002794:Choline; D014805:Vitamin B 12; D010100:Oxygen