process for the preparation of fermentatievloeistoffen with increased vitamin b12 content by means of synchronizing of the bacterial population. bacterial population.process for the preparation of fermentatievloeistoffen with increased vitamin b12 content by means of synchronizing of the bacterial population.

摘要

The invention relates to a process for the production of a fermentation broth with increased vitamin B12 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 B12 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 1.5 v/v% of methanol are added to the fermentation broth, and subsequently a minor part, preferably 10% of the fermentation broth, is removed daily and an equal volume of a nutrient broth containing the usual components in the usual concentrations is added together with 0.4 to 1.5 v/v % of methanol, depending on the biogas production of the fermentation broth. This series of operations is repeated periodically during the complete fermentation procedure taking into consideration the pH of the fermentation broth.