Effect of the cyclopeptolide 90-215 on the production of destruxins and helvolic acid by Metarhizium anisopliae

The effect of the cyclopeptolide 90-215 on the production of destruxins and helvolic acid in various Metarhizium anisopliae strains was investigated. Addition of 10.0 mg L⁻¹ of the cyclopeptolide to the production media increased the production of destruxins by 1.3-fold to 12.5-fold, whereas the production of helvolic acid was decreased by 1.6- to 11.0-fold. Fifty liters were fermented in Erlenmeyer flasks with the strain 86-23766 grown in medium supplemented with cyclopeptolide 90-215. The procedure for isolation and purification of destruxins was simplified due to the higher yield of destruxins. Good quantities of destruxins were obtained from this fermentation. The results of our studies show that the addition of small quantities of a suitable compound can drastically alter the production and relative ratios of secondary metabolites. This can have a wide range of potential applications in the area of metabolite production. Received 09 December 1996/ Accepted in revised form 09 April 1997