Strain and Medium

B. bassiana CCN-A7, a derivative of B. bassiana ZJB16001 [7, 13] was used for HPOPA production in this study.

Potato dextrose agar medium (PDA) was composed of 200 g/l potato, 20 g/l glucose, and 20 g/l agar. Potato dextrose broth medium (PDB) was similar to PDA, except that agar was absent.

The initial fermentation medium was composed of 20 g/l glucose, 5 g/l yeast extract, 5 g/l (NH₄)₂SO₄, 0.5 g/l MgSO₄•7H₂O, 0.05 g/l MnSO₄•H₂O, 1.5 g/l KH₂PO₄, 3.6 g/l K₂HPO₄•3H₂O, 1 ml/l microelement solution (2 g/l FeSO₄•7H₂O, 100 mg/l ZnSO₄•4H₂O, 300 mg/l H₃BO₃, 200 mg/l C°Cl₂•6H₂O, 10 mg/l CuCl₂•2H₂O, 20 mg/l NiCl₂•6H₂O, 30 mg/l Na2MoO₄•2H₂O), and 20 g/l POPA, pH 6.8.