Optimization of the Production Medium for Biosynthesis of Antifungal Antibiotic Ak-111-81 by Phosphate-Deregulated Mutant of <Emphasis Type="Italic">Streptomyces hygroscopicus</Emphasis>

Experimental mathematical designs were applied for optimization of a nutrient medium for biosynthesis of the antifungal antibiotic AK-111-81 by phosphate-deregulated mutant of Streptomyces hygroscopicus 111-81. Antifungal antibiotic AK-111-81 possesses well-expressed activity against Fusarium graminearum and other phytopathogenic fungi. The level of the production of the antibiotic AK-111-81 on this medium is more than three times higher than on the initial medium. The optimized quantitative composition of the nutrient culture media is (g/l): glucose, 20; soy meal, 18; ammonium succinate, 3; CaCO₃, 1.