Fig. 3.

Verification of different gene functions by yeast heterologous expression and substrate feeding of gene deletion mutants of B. bassiana. (A) Conversion of OA by the yeast cells expressing the OpS4 gene led to the formations of 3 and 5. (B) Nonenzymatic conversion of 3 to 5. Inset shows the ratio change of the two compounds after an aeration treatment for 1 h. (C) Failure of conversion of 5,5′-dideoxy-oosporein (5) by OpS7. The yeast cells expressing or not expressing the OpS7 gene were supplemented with 5 (at a final concentration of ∼10 μg/mL) for 24 h. (D) Restoration of oosporein production by ΔOpS7::OpS3 after addition of compound 6.