METHOD FOR PREPARING A VITAMIN B12 CRUDE PRODUCT

A method for preparing a vitamin B12 crude product, comprising: filtering pseudomonas denitrificans after acidification, hydrolysis, and flocculation sedimentation, and respectively collecting filter residues and a filtrate; leaching the filter residues by using an acetone composite solvent and then performing centrifugation treatment, and performing reduced-pressure concentration to obtain a leached concentrated solution; mixing the leached concentrated solution with the filtrate, adsorbing the mixture by using a macroporous resin, analyzing the mixture by using an acetone aqueous solution, and performing reduced-pressure concentration to obtain a cobamamide analyzed concentrated solution; adding a cyanamide aqueous solution for conversion, and then performing secondary flocculation sedimentation and filtration to obtain a vitamin B12 filtrate; adding an acetone crystal to the vitamin B12 filtrate, and performing suction filtration and drying to obtain a vitamin B12 crude product. Cobamamide is extracted by