Chen_2019_Int.Biodeterior.Biodegradation_136_34

AOPP herbicides are widely used against monocotyledonous weeds in agriculture. In this study, the Sphingobium sp. strain C3 was isolated from an AOPP herbicide-contaminated soil and was able to transform various AOPP herbicides, including the most commonly used AOPP herbicide, Fenoxaprop-p-ethyl (FE). The appH gene involved in the transformation of FE to fenoxaprop acid (FA) was cloned from strain C3. AppH showed 23-36% identity with other alpha/beta-hydrolases and belongs to subfamily of bacterial esterases. The recombinant AppH, which was highly expressed and purified, was able to transform many AOPP herbicides and p-nitrophenyl esters. AppH showed the highest catalytic activity towards Clodinafop-propargyl among the AOPP herbicides tested, and the catalytic activity decreased with the increase in the aliphatic chain length of AOPP herbicides. This study provides a new bacterial strain and a novel esterase for the initial hydrolysis of AOPP herbicides.