Method for producing vitamin B12 from hydrogen-metabolizing methane bacterium

摘要

Mesophilic methane bacteria obtained from digested sludge are acclimatized in an H₂/CO₂ medium and the acclimatized methane bacteria are grown on a support inclusive of inorganic nutritional salts of trace metal elements by using an immobilized bed bioreactor. The grown bacteria are allowed to metabolize a mixed gas, prepared by adding hydrogen to at least one of coal gas and biogas, into methane and at the same time, cobalamin contained in the fermented liquor is recovered as an extracellular product in the form of cyanocobalamin by using potassium cyanide to thereby produce vitamin B₁₂ efficiently in a high content and high yield.