摘要
Microorganisms are crucial in the bioremediation of organophosphorus pesticides. However, most functional microorganisms (> 99%) are yet to be cultivated. This study applied two cultivation-independent approaches, DNA-SIP and magnetic-nanoparticle mediated isolation (MMI), to identify the functional microorganisms in degrading dimethoate in agricultural soils. MMI identified five dimethoate degraders: Pseudomonas, Bacillus, Ramlibacter, Arthrobacter, and Rhodococcus, whereas DNA-SIP identified three dimethoate degraders: Ramlibacter, Arthrobacter, and Rhodococcus. Also, MMI showed higher resolution than DNA-SIP in identifying functional microorganisms. Two organic phosphohydrolase (OPH) genes: ophC2 and ophB, were involved in dimethoate metabolism, as revealed by DNA-SIP and MMI. The degradation products of dimethoate include omethoate, O,O,S-trimethyl thiophosphorothioate, N-methyl-2-sulfanylacetamide, O,O-diethyl S-hydrogen phosphorodithioate, O,O,O-trimethyl thiophosphate, O,O,S-trimethyl thiophosphorodithioate, and O,O,O-trimethyl phosphoric. This study emphasizes the feasibility of using SIP and MMI to explore the functional dimethoate degraders, expanding our knowledge of microbial resources with cultivation-independent approaches.
基金
The authors would like to thank the National Natural Science Foundation of China(Nos.42177359 and 41807119)
the Natural Science Foundation of Beijing(No.8212030)
the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-20-010A3 and FRF-IDRY-22-001)
the Open Fund of National Engineering Laboratory for Site Remediation Technologies(No.NEL-SRT201907).