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.

Abstract: The invention relates to a process for the production of a fermentation broth with increased vitamin B.sub.12 content by a fermentation process carried out with a methane-producing mixed bacterium population under anaerobic septic conditions in the presence of known nutrient components and precursors. According to the invention, methanol, preferably in an amount of 0.5 v/v %, is added for some days, preferably for 3 days to the fermentation broth containing vitamin B.sub.12 used as the starting substance. Thereafter a minor part, preferably 10% of the fermentation broth, is removed and an equal volume of a nutrient broth containing the usual components in tenfold concentrations is added periodically in every 5th to 12th day, then the removal of fermentation broth is interrupted for 0 to 2 days, preferably for 1 day, and only 0.4 to 1.

Abstract: The invention relates to a method for increasing the vitamin B.sub.12 production of fermentation processes performed in a known way with a mixed population of mesophilic methane-producing bacteria under anaerobic conditions. According to the invention in an enrichment period of preferably 4 to 7 days a nutrient concentrate containing mainly inorganic ammonium compounds as nitrogen source and mainly methanol as carbon source and having a N:C weight ratio of 1:10 to 1:20, preferably 1:11 to 1:15 is added in daily portions to a fermentation broth obtained from a usual vitamin B.sub.12 fermentation process and containing living bacterium populations so as to increase the total concentration of assimilable nitrogen by a factor of maximum 4 until the end of the enrichment period, and thereafter the fermentation is terminated and the obtained fermentation broth with an increased vitamin B.sub.