Abstract

Some factors on sporulation of Lecanicillium lecanii CA-1-G by one-time-at-a-factor have been studied. These factors include carbon and nitrogen sources, carbon-to-nitrogen ratios, mineral elements and vitamins together with water potentials, temperatures, dark/light cycles and pHs. On the basis of these results, together with “two-step” cultivation and orthogonal method, we optimized the culture conditions for sporulation of this fungus: inoculated with spore suspension on the basal medium ematophagous fungi (sucrose 19.00 gl^-1, soy peptone 4.06 gl^-1, K₂HPO₄ 1.00 gl^-1, KCl 0.50 gl^-1, MgSO₄ 0.50 gl^-1, FeSO₄ 0.01 gl^-1and agar 13.00 gl^-1) for 4 days, then transferred to sporulation medium (glucose 9.08 gl^-1, soy peptone 10.00 gl^-1, CuSO₄·5H₂O 0.01 gl^-1, ZnSO₄·7H₂O 0.05 gl^-1, CaCl₂ 1.00 gl^-1, H₃BO₄ 0.005 gl^-1, Na₂MoO₄ 0.005 gl^-1 and agar 13.00 gl^-1) for another 4 days with the environmental conditions of -7.3 MPa/pH 4/light 24 h/temperature 29°C for sporulation and -7.3 MPa/pH 3/light 12h/temperature 23°C for mass production. This research reflects on some physiology on nutrients and environmental characteristics of this fungus, and also gives the essential information for its industrialization.

Key words: Biocontrol, biomass, environment, L. lecani, nutrition, sporulation.