Pesticide Biodegradation Catalyzed by a Cold-Adapted Acetylxylan Esterase Identified from a Metagenome-Assembled Genome

This study identified a putative cold-adapted acetylxylan esterase in <i>Glutamicibacter soli</i> Em07 via a metagenome-assembled genome. The gene encoding this enzyme was cloned and heterologously expressed in <i>Escherichia coli</i>. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that the protein has a molecular weight of 33.24 kDa. Using 1-naphthyl acetate as a substrate, the enzyme activity was optimal at 20 °C and pH 9. Furthermore, the enzyme exhibited excellent cold adaptation, alkali resistance, and salt tolerance. It demonstrated OCP pesticide-degrading activity: 66.48% degradation of carbaryl, 92.14% of cypermethrin, and 97.78% of malathion, underscoring its strong potential in environmental remediation. Notably, this esterase emerged as the first to simultaneously possess cold adaptation, alkali resistance, and salt tolerance. These results positioned the enzyme as a promising candidate for bioremediation strategies in multiextreme environments. Further research will investigate its activity on other persistent organic pollutants.