Effect of different pH values on growth and sporulation of Estye vermicola

Esteya vermicola, an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against pinewood nematodes. In order to improve the growth rate, sporulation and proportion of lunate conidia, the optimization of pH value for E. vermicola was tested. The diameter and dry mass of E. vermicola in PDA medium were increased greatly at pH 5 after 15 days, while the diameter and dry mass of E. vermicola were inhibited at pH 9 and 10. The sporulation of E. vermicola in PDA or PDB medium was highest at pH 6, 2.0 × 10 7 and 1.4 × 10 7 CFU/ml, respectively. The proportion of lunate conidia in PDA medium was highest at pH 4, while the proportion of lunate conidia in PDB medium was highest at pH 7.