Abstract
This study aimed to isolate, purify, and identify some bacteria from different sources known to be contaminated with pesticides and evaluate their ability to degrade two important pesticides, chlorantraniliprole (CAP), and flubendiamide (FBD). In our study, six isolates showed maximum growth in the presence of CAP and FBD in the growth media as a sole carbon source. The isolates were purified and then identified by biochemical and morphological tests, MALD-TOF-MS, and 16S rRNA techniques, as Bacillus subtilis subsp. subtilis AZFS3, Bacillus pumilus AZFS5, Bacillus mojavensis AZFS15, Bacillus paramycoides AZFS18, Pseudomonas aeruginosa KZFS4, and Alcaligenes aquatilis KZFS11. The degradation ability of studied bacterial strains against pesticides was estimated under different conditions (temperatures, pH, salt, and incubation time). The results reveal that the optimal conditions for all bacterial strains’ growth were 30−35 °C, pH 7.0, 0.0−0.5% NaCl, and an incubation period of 11 days at 150 rpm in the presence of diamide insecticides at 50 mg/L. The capacity of six bacterial strains of CO2 production and degradation ability against various diamide pesticides and other pesticide groups (Profenofos, Cypermethrin, Carbofuran, and Malathion) were evaluated. The results show that the Pseudomonas aeruginosa KZFS4 (LC599404.1) strain produced the highest CO2 content, about 1.226 mg CO2/16 day, with efficacy in the biodegradation of FBD-CAP (78.6%), while the absorbance of bacterial growth (OD 600) on various pesticides ranged from 1.542 to 1.701. Additionally, Consortium-(No. 3)-mix-6-strains gave 1.553 mg CO2/16 days with efficacy (99.6%) and turbidity of 2.122 to 2.365 (OD 600) on various pesticides. In conclusion, the six bacterial strains could play an important role in the biodegradation process of pollutants in soils.