Istamycins and streptomyces culture for the production thereof

The process of producing istamycin A which comprises cultivating a microorganism having the identifying characteristics of Streptomyces tenjimariensis SS-939, identified as FERM-P 4932 or ATCC 31603, under aerobic conditions in a culture medium containing assimilable sources of carbon and nitrogen until a substantial amount of istamycin A is produced and accumulated in the culture medium.

The process of producing istamycin B which comprises cultivating a microorganism having the identifying characteristics of Streptomyces tenjimariensis SS-939, identified as FERM-P 4932 or ATCC 31603, under aerobic conditions in a culture medium containing assimilable sources of carbon and nitrogen until a substantial amount of istamycin B is produced and accumulated in the culture medium.

The process of producing istamycin A.sub.o which comprises cultivating a microorganism having the identifying characteristics of Streptomyces tenjimariensis SS-939, identified as FERM-P 4932 or ATCC 31603, under aerobic conditions in a culture medium containing assimilable sources of carbon and nitrogen until a substantial amount of istamycin A.sub.o is produced and accumulated in the culture medium.

The process of producing istamycin B.sub.o which comprises cultivating a microorganism having the identifying characteristics of Streptomyces tenjimariensis SS-939, identified as FERM-P 4932 or ATCC 31603, under aerobic conditions in a culture medium containing assimilable sources of carbon and nitrogen until a substantial amount of istamycin B.sub.o is produced and accumulated in the culture medium.

A biologically pure culture of the microorganism, Streptomyces tenjimariensis SS-939, identified as FERM-P 4932 or ATCC 31603 which is capable of producing the antibiotic, istamycin complex, in a recoverable quantity upon cultivation in a culture medium containing assimilable sources of carbon and nitrogen under aerobic conditions.