Bioremediation of insecticides acetamiprid and sulfoxaflor co-contamination by Ensifer sp. DA6 and characterization of the novel nitrile hydratase involved

Wenlong Yang^1*Jia Kang¹Yahui Shao¹Yun Geng¹Yingxin Zhang¹Renlu Liu^2*Gao Chen^1*

• ¹Shandong Academy of Agricultural Sciences, Jinan, China
• ²Jinggangshan University, Ji'an, China

The co-contamination of the neonicotinoid insecticide acetamiprid (ACE) and the sulfoximine insecticide sulfoxaflor (SUL) poses a threat to ecosystem integrity and environmental security. Microbial remediation of ACE and SUL co-contamination has not been studied. Here, bacterial isolate DA6, which converts ACE to (E)-N2-carbamoyl-N1-[(6-chloro-3-pridyl) methyl]-N1-methylacetamidine (IM-1-2) and converts SUL to N-(methyl(oxido){1-[6-(trifluoromethyl)pyridin-3-yl] ethyl}-k4-sulfanylidene)urea (X11719474), was isolated and identified as Ensifer sp. DA6. Immobilized Ensifer sp. DA6 showed ACE and SUL degradation activity in Yellow River water. The genome of Ensifer sp. DA6 contained a nitrile hydratase (NHase) gene cluster. The recombinant Escherichia coli strain harboring the Ensifer sp. DA6 NHase gene and the purified NHase acquired the ACE and SUL degrading ability. The NHase of Ensifer sp. DA6 is a typical cobalt-containing NHase with subunit alpha, subunit beta and an accessary protein. The three-dimensional homology model of NHase was built and the active sites were predicted. This is the first report of microbial degradation of ACE and SUL co-contamination and characterization of the novel NHase involved.