Establishment of beet molasses as the fermentation substrate for industrial vitamin <scp>B₁₂</scp> production by <i>Pseudomonas denitrificans</i>

Abstract

Abstract BACKGROUND Fermentation of the industrial vitamin B 12 by Pseudomonas denitrificans usually utilizes sucrose or maltose as the sole carbon source, which results in increased medium costs. In order to decrease the fermentation cost, it is crucial and essential to employ a low‐cost and convenient raw material as an alternative medium substrate for industrial vitamin B 12 production . RESULTS The results obtained in chemically defined medium showed that glutamate and sucrose were favorable for cell growth and vitamin B 12 biosynthesis of P. denitrificans . Due to containing a mass of ingredients such as sucrose, glutamate and betaine, beet molasses was consequently chosen as the main medium substrate for industrial P. denitrificans fermentation in a 120 000 L fermenter. Vitamin B 12 production reached 181.75 mg L –1 . CONCLUSIONS Beet molasses is a by‐product of the sugar industry and is thus very inexpensive, and it was proved that beet molasses was an efficient and economical medium substrate for industiral vitamin B 12 fermentation by P. denitrificans . © 2013 Society of Chemical Industry