Japan Science and Technology Corporation (Saitama, Japan) has
patented 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. (US 6,972,188)