Distribution and Evolutionary Signatures of a Broad‐Spectrum Pesticide‐Degrading Carboxylesterase TriS From Strain S113

Ester‐containing pesticides, such as diphenyl ether herbicides, aryloxyphenoxypropionate herbicides, and strobilurin fungicides, are widely applied in agriculture, but their residues pose significant risks to ecosystems. Functional microorganisms can degrade ester‐containing pesticides in the natural environment. However, the microbial mechanisms responsible for their degradation in soils remain unclear. A novel hydrolase gene triS from the strain S113 encoded a broadly active carboxylesterase that hydrolyzes a wide range of ester‐containing pesticides. TriS exhibited a maximum sequence similarity of 34.92% to proteins in the Swiss‐Prot (UniProt) database. Gene redundancy was observed in strain S113, with TriS showing higher catalytic activity than its homologues. The enzyme contains a conserved Ser226‐Glu346‐His456 catalytic triad, and its substrate‐binding pocket can accommodate complex substrates, which contributes to its broad substrate spectrum and enhanced catalytic efficiency. Genomic analyses revealed that triS resides in a conserved locus, whereas related paralogs occupy more variable regions, suggesting potential horizontal dissemination. Bioinformatics‐based taxonomic profiling showed widespread occurrence of TriS homologues, mainly in agricultural soils, and also in forests and wetlands, indicating spread beyond pesticide‐treated fields. This study elucidated the function and distribution pattern of triS , enhancing our understanding of microbial ester‐containing pesticide degradation in the environment. A novel carboxylesterase, TriS, from strain Hansschlegelia zhihuaiae S113 degrades a wide range of ester‐bonded pesticides. Its structural features and widespread presence in both farmlands and natural areas help explain how microbial communities adapt to chemical stress and maintain key detoxification functions in the environment.