In-depth biochemical identification of a novel methyl parathion hydrolase from Azohydromonas australica and its high effectiveness in the degradation of various organophosphorus pesticides

• Published in: Bioresource technology 2021-03, Vol.323, p.124641, Article 124641
• Main Authors: Zhao, Sumao, Xu, Wei, Zhang, Wenli, Wu, Hao, Guang, Cuie, Mu, Wanmeng
• Format: Article
• Language: English
• Subjects: Alcaligenaceae; Bioremediation; Chlorpyrifos; Humans; Hydrolases; Methyl Parathion; Methyl parathion hydrolase; Organophosphorus Compounds; Organophosphorus pesticides; Pesticides; Thermostability
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.124641

[Display omitted] •A novel methyl parathion hydrolase was investigated.•Leveraging 1 mM Mn2+, the enzymatic activity would be significantly enhanced.•Co-incubation of 1 mM Mn2+ would greatly increase the Tm of free-enzyme.•The MPH showed high effectiveness in the degradation of various OPs pesticides. Organophosphorus pesticides are highly toxic phosphate compounds with the general structure of O = P(OR)3 and threaten human health seriously. Methyl parathion hydrolase from microbial is an important enzyme to degrade organophosphorus pesticides (OPs) into less toxic or nontoxic compounds like. p-nitrophenol and diethyl phosphate. Here, a gene encoding methyl parathion hydrolase from Azohydromonas australica was firstly cloned and expressed in Escherichia coli. The recombinant hydrolase showed its optimal pH and temperature at pH 9.5 and 50 °C. Leveraging 1 mM Mn2+, the enzyme activity was significantly enhanced by 29.3-fold, and the thermostability at 40 and 50 °C was also improved. The recombinant MPH showed the specific activity of 4.94 and 16.0 U/mg towards methyl parathion and paraoxon, respectively. Moreover, A. australica MPH could effectively degrade various of OPs pesticides including methyl parathion, paraoxon, dichlorvos and chlorpyrifos in a few minutes, suggesting a great potential in the bioremediation of OPs pesticides.