Patent ID: 8114642

Claim:
A method for producing vitamin K2, comprising: culturing Bacillus natto in a liquid medium to obtain a Bacillus natto culture or culture supernatant thereof, wherein the culture or culture supernatant contains vitamin K2; treating the Bacillus natto culture or culture supernatant with an inorganic coagulant in combination with a phosphorus-containing coagulant, wherein the inorganic coagulant is calcium chloride and the phosphorus-containing coagulant is at least one selected from the group consisting of disodium hydrogenphosphate, sodium dihydrogenphosphate, potassium dihydrogenphosphate and tripotassium phosphate, so as to form a coagulant to which vitamin K2 from the Bacillus natto culture or culture supernatant is absorbed or aggregated; separating the coagulant to which vitamin K2 is absorbed or aggregated from the treated culture or culture supernatant; treating the coagulant to which vitamin K2 is absorbed or aggregated with an organic solvent for extraction; collecting an organic solvent extract; removing the organic solvent from the organic solvent extract; and obtaining an oily product that contains vitamin K2 from the extract from which the organic solvent has been removed.