Novel process for producing antibiotics bleomycin

Abstract

A novel process for producing antibiotics bleomycins by innoculating and aerobically culturing in a nutrient source-containing medium a bleomycin-producing strain belonging to the actinomyces, wherein the culture is effected in the presence of an amino compound having at least one ##STR1## group and at least one basic group selected from amino, imino, guanidino, amidino and sulfonium groups and nitrogen-containing cyclic compounds, or in the presence of a compound convertible in the culture liquor to such amino compound as mentioned above, thereby selectively producing a known or novel bleomycin component corresponding to the said amino compound or to an amino compound derived from the above-mentioned compound, and then the known or novel bleomycin is recovered by known means from the culture medium.

What is claimed is: 
     
       1. Bleomycins having a structure represented by the formula, ##STR98##