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Dalesconols (dalesconols A andB) are novel polyketides with strong immunosuppressive activity produced by Daldinia eschscholzii.In this work, the effects of different media (M1, M2, and M3) on fungus growth and dalesconolsbiosynthesiswerefirstly tested and compared.Intermediates and enzyme analysis indicated that laccase had the major contribution to dalesconols biosynthesis.The key role oflaccase on dalesconols biosynthesiswas further experimentally confirmed, which suggested that the modified M2 was more favored for laccase and dalesconols production.Thereafter, the medium composition was optimized by RSM with a fermentation titer of 36.66 mg/L obtained.Furthermore, Ca2+induction was employed to up-regulate of laccase activity and further enhanced dalesconols production(76.90 mg/L), which was 308% higher than that in M2.In addition, dalesconols production reached 63.42mg/L in scale-up experiments.This work indicates great potential of laccaseas a key enzyme on regulation of dalesconols production.