A Novel Nutrient Deprivation-Induced Neonicotinoid Insecticide Acetamiprid Degradation by Ensifer adhaerens CGMCC 6315

Proteomic Analysis. The proteomic expression of CGMCC 6315 under different nutrient concentration conditions was investigated by isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics. The CGMCC 6315 was cultured in LB broth and 1/15LB broth as described above, after which the strains were collected by centrifugation at 10,000× g for 10 min at 4°C. Protein extraction, digestion, iTRAQ labeling and peptide fractionation were performed using the protocol described by Jin et al. 29. Protein identification was conducted using a LC-20AD nano-HPLC instrument (Shimadzu, Kyoto, Japan) equipped with a Q EXACTIVE tandem mass spectrometer (Thermo Fisher Scientific, San Jose, CA, USA) for data-dependent acquisition detection by nano-electrospray ionization. The raw MS/MS data were converted into MGF format by the thermo scientific tool Proteome Discoverer, and the exported MGF files were searched using Mascot (version 2.3.02) against the selected database containing 7546 CGMCC 6315 coding genes. The IQuant software was used for quantitative analysis of the labeled peptides with isobaric tags. Fold changes of >1.7 with p-values <0.05 were used as a cut off for differentially regulated proteins.