Abstract: A fermentation process is disclosed for the preparation of an inoculum, suitable for batchwise, semicontinuous, or continuous production of coenzyme B.sub.12 under septic conditions. The fermentation process begins with a broth consisting of methanol, cornsteep liquor hydrolysate or heat-treated corn slop, ammonium bicarbonate, magnesium chloride, cobalt chloride, 5,6-dimethyl-benzimidazole and sodium bisulfite used for anaerobic, mesophilic, septic fermentation production of coenzyme B.sub.12 with anaerobic, digested sewage sludge. Fermentation is carried out over several steps to provide an inoculum containing an anaerobic, mesophilic, methane-producing, new mixed micropopulation, containing bacteria of each of the types deposited at the Hungarian National Collection of Medical Bacteria, National Institute of Hygiene, under numbers 00076, 00079, and 00272.

Abstract: The invention relates to a process for the preparation of a fermentation broth containing coenzyme B.sub.12, with a new, anaerobic, mesophilic, methane-producing mixed micropopulation, under anaerobic, septic conditions, using a new broth containing methanol, precursors and partially known nutrients,In the new process according to the invention the improvement consists in(a) removing 5 to 15 volume percent of the inoculum fermentation broth containing the anaerobic, mesophilic, methan-producing new mixed micropopulation and replacing same with an equal volume of a broth containing cornsteep liquor hydrolysate and/or corn slops of hydrolysate thereof and other known nutrients, the number and concentration of which has been reduced, for 6 to 8 days, and if desired, further manufacturing the fermentation broth removed,(b) after reaching an assimilation velocity of at least 0.15 to 0.2 g methanol/lit.