BioChem - DOS

Improved propionic acid and 5,6-dimethylbenzimidazole control strategy for vitamin B12 fermentation by Propionibacterium freudenreichii

Journal of biotechnology

Wang, Peng; Zhang, Zhiwei; Jiao, Youjing; Liu, Shouxin; Wang, Yunshan

<P><B>Abstract</B></P> <P>An efficient fermentation-strengthening approach was developed to improve the anaerobic production of vitamin B12 by cultivation process optimization with <I>Propionibacterium freudenreichii.</I> The effects of the byproduct propionic acid and the precursor 5,6-dimethylbenzimidazole (DMB) on vitamin B12 biosynthesis were investigated. Byproduct inhibition experiments showed that maintaining propionic acid concentration in broth below 10&ndash;20g/L in the early stage and 20&ndash;30g/L in the late stage can efficiently improve vitamin B12 biosynthesis. Batch fermentation indicated the occurrence of feed-back inhibition in intracellular intermediate biosynthesis. In addition, the incorporation of the precursor DMB depended on the fermentation level of the vitamin B12 intermediate. High vitamin B12 concentration (58.8mg/L) and production (0.37mg/g) were obtained with an expanded bed adsorption bioreactor by using the propionic acid and DMB control method. The optimum concentration and production of 59.5？and 0.59mg/L？h for vitamin B12 production were respectively achieved after five continuous batches.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Controlling propionic acid concentration could improve vitamin B12 biosynthesis. </LI> <LI> Feed-back inhibition occurred in intermediate biosynthesis of vitamin B12. </LI> <LI> Vitamin B12 biosynthesis increased upon the addition of DMB. </LI> <LI> Propionic acid and DMB control strategy could improve vitamin B12 biosynthesis. </LI> <LI> Vitamin B12 productivity of 0.59mg/L/h was obtained by repeated batch fermentation. </LI> </UL> </P>

2015

Elsevier

0168-1656

1873-4863

193

pp.123-129

10.1016/j.jbiotec.2014.11.019

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART71058891

Vitamin B12; Propionic acid; 5,6-Dimethylbenzimidazole; Feed-back inhibition; Expanded bed adsorption bioreactor