BIOSYNTHESIS OF COBALAMINS BY CELL SUSPENSIONS OF PROPIONIBACTERIA AND STREPTOMYCETES

Abstract

When washed cell suspensions of Propionibacterium arabinosum (ATCC 4965), P. freudenreichii (ATCC 6207), P. pentosaceum (ATCC 4875), Streptomyces aureofaciens (NRRL B-2209), S. fradiae (Waksman 3535), S. griseus (Waksman 4), S. rimosus (NRRL B-2234), and Streptomyces sp. ATCC 11,071 were mixed with solutions containing cobalt salts, significant quantities of cobalamins were formed. The cobalamin synthesized by the P. freudenreichii and streptomycete cells was identified by paper chromatography and ionophoresis as 5,6-dimethylbenzimidazole-hydroxo cobalamin, and that in the cells of the P. arabinosum and P. pentosaceum cultures was shown to be adenine-hydroxycobalamin. When cell suspensions of the latter organisms were mixed with cobalt solutions and solutions of 5,6-dimethylbenzimidazole the cobalamin synthesized was 5,6-dimethylbenzimidazole-hydroxyocobaIamin. When benzimidazole, 5-methylbenzimidazole, phenothiazine, quinoxaline, 2-hydroxyphenazine, or a,a,a,-trifluoromethyl-2-nitro-p-toluidine was added to the cell suspensions of P. arabinosum or P. pentosaceum instead of the 5,6-dimethylbenzimidazole, the cobalamins formed contained these substances in the nucleotide portion of the molecule according to the paper chromatographic analyses.