New production of fk-506

PURPOSE: To obtain an FK-506 immunosuppressant by culturing a strain of a Streptomyces sp. ATCC No. 55098 in a liquid hydrocarbon culture medium containing a nitrogen nutrient under submerged aerobic fermentation conditions for a time sufficient to produce the FK-506. CONSTITUTION: A streptomyces sp. strain ATCC No. 55098 is cultured in a liquid hydrocarbon culture medium containing a nitrogen nutrient under submerged aerobic fermentation conditions for a time sufficient to produce FK-506 to thereby afford an immunosuppressant immobilized as the FK-506. An FKA fermenting culture medium is preferred as the culture medium. COPYRIGHT: (C)1993,JPO