Determination of optimum conditions for antibiotic production by Streptomyces galbus

The nutritional requirements and cultural conditions for optimal production of a new extracellular antifungal antibiotic by Streptomyces galbus under laboratory conditions were determined. Glycerol and glucose were found to be the best carbon sources, while as N-source nitrate was preferred. Maximum titre was reached after 7 d of incubation at 30 degrees C at pH 6.8 The metal ions Cu2+, Zn2+, and Fe2+ had some promoting effect. Casein hydrolysate improved production, but yeast extract markedly inhibited. Growth in shake flasks favoured higher yield of the antibiotic in a shorter time.