High-level expression of zearalenone lactonohydrolase ZenG in Pichia pastoris via combinatorial strategy

Zearalenone contamination poses a continuing threat to food security and the health of the livestock industry; developing efficient, high-yield detoxifying enzyme formulations is therefore essential. This study aimed to achieve the high-level expression of zearalenone lactonohydrolase ZenG in Pichia pastoris. The resulting recombinant ZenG exhibited optimal activity at pH 8.0 and 50 °C, with a specific activity of 684 ± 2.17 U/mg. Replacing the α-factor signal peptide with the pre-Ost1-pro-α-factor signal peptide increased ZenG activity from 180.26 U/mL to 276.47 U/mL. Subsequent optimization of the gene dosage further boosted the yield to 479.52 U/mL. Co-expression of the molecular chaperones 100p-HAC and 55p-HAC1 elevated the enzyme activity to 557.85 U/mL and 582.01 U/mL, which correspond to 3.09-fold and 3.23-fold increases, respectively, compared to the initial G-α-ZenG strain. In conclusion, this study successfully constructed an engineered P. pastoris strain capable of highly efficient ZenG production, laying a solid foundation for its industrial-scale application.