PRODUCTION OF VITAMIN B12 BY CULTURE OF MICROORGANISM AT HIGH CONCENTRATION

摘要

PURPOSE:To obtain highly concentrated cells of a vitamin B12-producing microbial strain and to easily produce a large amount of vitamin B12, by culturing a vitamin B12-producing microbial strain using a hollow-fiber microfilter module. CONSTITUTION:A vitamin B12-producing microbial strain is cultured in a liquid medium containing a small amount of a cobalt salt by batch process to obtain a strain for inoculation. The strain is inoculated at an amount of about 0.01-0.3 (in terms of O.E570) to a main culture tank containing a similar liquid medium and subjected to main culture. The cultured liquid is filtered with a hollow fiber micromodule (e.g. Microsa pw-303, pw-103) immediately before the growth the strain is slowed down or terminated. The liquid is separated into a liquid containing microbial cells and a liquid free from cells by this filtration. The liquid containing microbial cells is returned to the main culture tank and a liquid free from cells to cause the inhibition of growth is successively extracted from the tank. A fresh liquid medium of the volume equal to the volume of the extracted liquid is continuously supplied to the culture tank and the filtration and the culture are continued to obtain a cultured liquid containing microbial cells at high concentration. The B12 can be continuously produced by extracting the culture liquid while replenishing the fresh medium to the tank.