1974 Volume 27 Issue 12 Pages 917-921
A mutant of Micromonospora inyoensis, the sisomicin-producing organism, has been isolated which requires the addition of 2-deoxystreptamine to the fermentation broth for sisomicin production. The addition of analogues of 2-deoxystreptamine to this mutant resulted in the formation of new antibiotics called mutamicins. Mutamicin 1, produced by the addition of streptamine to the fermentation broth, exhibits broad-spectrum activity with potency similar to or slightly less than sisomicin, with the exception of gentamicin-sisomicin-adenylylating strains against which mutamicin 1 exhibited greatly improved activity. Mutamicin 2, produced by the addition of 2, 5-dideoxystreptamine, exhibits similar broad-spectrum activity but with favorable activity against gentamicin-sisomicin-acetylating strains.