Studies on new aminoglycoside antibiotics, istamycins, from an actinomycete isolated from a marine environment. I. The use of plasmid profiles in screening antibiotic-producing streptomycetes.

Plasmid profiles were used to screen streptomycetes for production of new antibiotics. Among about 100 strains isolated from sea muds, an isolate designated SS-939 was revealed to harbor several plasmids of different sizes, and to produce istamycins, new aminoglycoside antibiotics. Based on the characteristics of the strain, a new Streptomyces species is proposed: S. tenjimariensis.