Improved large-scale production of vitamin B 12 by Pseudomonas denitrificans with betaine feeding

Abstract

The strategy of betaine control for vitamin B 12 large-scale fermentation by Pseudomonas denitrificans was investigated in this paper. The results obtained in shake-flask experiments demonstrated that betaine could greatly stimulate vitamin B 12 biosynthesis but had an inhibition to cell growth. Based on the influence of betaine on the fermentation of P. denitrificans, betaine feeding was a beneficial strategy to solve the inconsistency between cell growth and vitamin B 12 production. As a result, an effective and economical strategy of betaine feeding was established for vitamin B 12 fermentation in 120-m 3 fermenter, in which betaine was continuously fed to maintain betaine concentration of the broth at the range of 5–7 g/l during 50–140 h of fermentation.