NOVEL YEAST AND ITS PRODUCTION

摘要

PURPOSE:To provide a novel yeast strain belonging to Candida genus, and capable of producing citric acid by assimilating xylose. CONSTITUTION:(A) A yeast strain belonging to Candida genus and assimilating hydrocarbons and citric acid [e.g. Candida lipolytica (IFO-0746)] and (B) a yeast strain belonging to Candida genus and assimilating xylose [e.g. Candida utilis (IFO-4277)] are treated with a yeast cell-dissolving enzyme, and are treated in an aqueous solution of polyethylene glycol to effect the protoplast fusion. The fused protoplast is cultured alternately in a minimum medium containing paraffinic hydrocarbons and a minimum medium containing xylose to obtain a yeast strain capable of producing citric acid by assimilating xylose [Candida NF-1 (FERM-P No.7265)].