High expression and characterization of a novel zearalenone hydrolase from Rhinocladiella mackenziei in Pichia pastoris

Abstract:

[Background] Zearalenone (ZEN) and its derivatives are a series of mycotoxins with estrogenic activity which are widespread in mold contaminated cereals. Mycotoxin contamination has caused huge loss to food and feed industries. To develop an efficient solution is an urgent task. [Objective] In order to promote the research and application of zearalenone hydrolase, we constructed the recombinant plasmid that highly expressed zearalenone hydrolase in Pichia pastoris. [Methods] The Rmzhd gene from Rhinocladiella mackenziei CBS 650.93 was transformed into Pichia pastoris GS115 for heterologous expression. The high expression strain was screened and the characterization of recombinant RmZHD was analyzed by high performance liquid chromatography (HPLC). [Results] The ZEN and α-ZOL degradation activities of the recombinant RmZHD from the supernatant were 16.67 U/mL and 9.85 U/mL, respectively. The molecular mass of RmZHD was about 30.7 kD, and the purity of protein was very high, as shown by SDS-PAGE. The optimal pH and temperature of recombinant RmZHD were determined as pH 9.6 and 45 °C, and RmZHD has a good thermostability. [Conclusion] The results can provide guidance for the heterologous expression and potential industrial application of zearalenone hydrolase.

Key words:Zearalenone hydrolase, Pichia pastoris, High expression, Enzymatic properties