Preliminary study on the optimization of seed culture medium for cycloheximide-producing strain YIM41004

The composition of seed culture medium and the culture conditions for cycloheximide-producing new strain Streptomyces yunnanensis YIM41004 were optimized.The optimum composition was as following:glucose 25?g,peptone 7.5?g,yeast extract 7.5?g,CaCO_3 3?g,MgSO_4·7H_2O 1?g,MnSO_4·4H_2O 0.1?g,KH_2PO_4 0.2?g,distilled water 1?000?mL.The optimal pH value was 7.8,the broth volume in 500?mL flask was 100?mL,and the optimal seed age was 32—36?h.Inoculated with 10%(V/V) seed broth and cultured with the optimized seed culture medium,the cycloheximide production level of flask ferrmentation reached up to 498.9?(mg·L~(-1)),which was 10.7%?higher than that cultured with the original seed broth culture.