Bioproduction of Axenomycins in Batch Cultures of Streptomyces lisandri

Abstract

The influence of various factors such as aeration, pH and size of the inoculum on production of axenomycin A, B, and D and on growth of Streptomyces lisandri was studied in batch cultures. An investigation of the nutritional requirements showed that growth and antibiotic production are not necessarily correlated. The yield of acenomycins was increased to 1.7 g per liter medium by repeated selection for a high producing strain. Bioautography showed that these strains produced a hitherto undescribed antibiotic and that all strains tested differed in the total amount of axenomycins produced but not in the composition of the fraction containing antibiotic activity. Addition to the medium of extra amounts of inorganic phosphate and various nitrogen sources showed that both nutritional components selectively inhibited axenomycin formation but did not inhibit growth of Streptomyces lisandri. Good growth of Streptomyces lisandri was observed in the presence of sucrose and its monomers (glucose, fructose), but whereas sucrose inhibited axenomycin formation almost completely, its monomers did not.