RAMULOSIN FERMENTATION

Hesseltine, C. W., C. R. Benjamin, Barbara Bradle, and W. F. Hendershot. (Northern Regional Res. Lab., Peoria, I11.) Ramulosin fermentation. Amer. Jour. Bot. 50(3): 209-213. Illus. 1963.—A nonsporulating strain of Pestalotia ramulosa v. Beyma NRRL 2826 produces large amounts of ramulosin, a compound having a molecular formula of C₁₀H₁₄O₃. This compound was first observed in colonies growing on malt extract agar and was subsequently produced in large yields in still fermentation at 15 C. Two other sporulating strains of this species fail to produce ramulosin, but all 3 strains have similar carbon and nitrogen utilization patterns. Of a number of different media tested, the best was found to be composed of 4.0% malt extract, 4.0% glucose and 0.1% peptone. Yields of as much as 6.2 g of ramulosin per liter of medium have been obtained, representing 58% of the total dry weight of the culture. Ramulosin is not produced in any appreciable amounts until after most of the mycelium is formed. Ramulosin can also be produced in submerged fermentations. A sporulating form that fails to produce ramulosin has been found incertain fermentations carried out at elevated temperatures.