Biodegradation of sulfoxaflor by Pseudomonas stutzeri CGMCC 22915 and characterization of the nitrile hydratase involved

• Published in: International biodeterioration & biodegradation 2022-05, Vol.170, p.105403, Article 105403
• Main Authors: Jiang, Huo-Yong, Wu, Hong-Kai, Yuan, Pan-Pan, Guo, Jing-Jing, Wang, Li, Dai, Yi-Jun
• Format: Article
• Language: English
• Subjects: Amides; Biodegradation; Bioremediation; Contamination; E coli; Enzymatic activity; Half-life; Insecticides; Nitrile hydratase; Pseudomonas; Pseudomonas stutzeri; Sediment pollution; Soil; Soil contamination; Soil degradation; Soil pollution; Soil water; Soils; Sulfoxaflor; Surface water; Thiacloprid
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2022.105403

Sulfoxaflor (SUL), a novel sulfoximine insecticide, causes environmental contamination and poses potential risks to animals. However, there are few reports of SUL degradation by pure microbes. In this study, a novel isolated bacterium, Pseudomonas stutzeri CGMCC 22915, rapidly degraded SUL to SUL-amide via hydration. P. stutzeri CGMCC 22915 degraded 58.2% of SUL (814.28 μmol/L) within 2 h with a half-life of 1.6 h. P. stutzeri CGMCC 22915 effectively facilitated SUL degradation in soil and surface water. The nitrile hydratase PsNHase with a different gene orientation of was responsible for the formation of SUL-amide from SUL and transformed other nitrile-containing insecticides thiacloprid and acetamiprid to their amides. Nitrile hydratases with this gene orientation have never been reported to degrade nitrile-containing insecticides. E. coli expressing PsNHase degraded 90.4% of SUL (798.29 μmol/L) within 5 min with a half-life of just 0.59 min. PsNHase showed the highest activity in SUL degradation among reported NHases (Vmax 21.69 U/mg, Km 1.62 mmol/L). Modeling of PsNHase suggested that β-His62 was important for its highest enzymatic activity toward SUL. P. stutzeri CGMCC 22915 is promising for application in the bioremediation of SUL in contaminated soil and surface water. [Display omitted] •P. stutzeri CGMCC 22915 rapidly degraded SUL via a hydration pathway.•P. stutzeri CGMCC 22915 effectively degraded SUL in surface water and soil.•The nitrile hydratase PsNHase transformed SUL to SUL-amide.•PsNHase showed the highest activity in SUL degradation among reported NHases.•PsNHase with a different gene orientation degraded nitrile-containing insecticides.