摘要:
This invention relates to the fields of microbiology and antibiotics. Particularly, it relates to a new mutant strain, a method of its mutation breeding, to a monocomponent Gentamicin C.sub.1a produced by this strain which is used as mother nucleus of semisynthetic antibiotic 1-N-ethylgentamicin C.sub.1a, and to compositions composed of semisynthetic 1-N-ethylgentamicin derivatives as active component and pharmaceutically acceptable accitives and their manufacturing methods.