Enhanced removal of fifteen pesticide mixture by a single bacterial strain using response surface methodology and its application in raw milk.

PURPOSE: Environmental contamination with various pesticides accompanied by uncontrolled use contributes to severe ecological and health problems. Although extensive research was conducted on pesticides degradation, very few reports have demonstrated the degradation of mixed pesticides. Consequently, this study aimed to evaluate the removal efficacy of highly potent bacterial isolate for pesticide mixture under optimal culture conditions, followed by their application in milk.
METHODS: Isolation and selection of bacterial isolates were performed from 40 milk samples by enrichment culture technique and were screened to obtain highly potent bacterial strain identified by 16 S rDNA analysis. The statistics-based experimental designs were applied to optimize the culture conditions towards the best degradation of pesticides mixture, followed by subsequent utilization in milk. The degradation ratio of pesticides was analyzed using gas chromatography-mass spectrometry.
RESULTS: In this study, a bacterial strain S6A identified as Bacillus subtilis-mw1 efficiently eliminated environmental contaminants from different groups of pesticide residues. The statistical optimization showcased optimum settings that accomplished the highest pesticide mixture degradation (61.59 %). The application experiment manifested that degradation of pesticide mixtures of sterile milk (STM) was relatively faster than non-sterile milk (NSTM).
CONCLUSIONS: The obtained results assist in eliminating environmental contamination with various groups of pesticide residues. Furthermore, it can be employed in reducing pesticide residues that cause milk contamination to increase safety and quality.Graphical abstract. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00683-0. © Springer Nature Switzerland AG 2021.