Effect of Culture Medium pH on Chlorpyrifos Biodegradation and Metabolic Profiles of a Novel Enterobacter strain

Chlorpyrifos (CPF) is a common agricultural pesticide used worldwide. As an agricultural pesticide, CPF has been used extensively and has resulted in significant contamination. Because it might leak into neighboring ditches or drains, which normally carry water to lakes and streams, it may be dangerous. The current work used the enrichment technique to isolate bacteria with a high capacity for degradation from agricultural drainage water (El-Batts drain), Fayoum, Egypt. Isolated bacteria identified as Enterobacter sp. n1 under Genbank accession number PV495863 based on morphological, biochemical, and 16S rRNA gene sequencing technique. Mineral salt media (liquid and solidified) supplemented with CPF as sole carbon and nitrogen source used for the growth of a pure culture of and Enterobacter sp. n1. Bacteria cell count and optical density were used to detect the growth. The effect of CPF concentrations (50, 75,100,125,150, and175ppm), pH values (5, 6, 7, 8, and 9), and temperatures (15, 20, 30, 35, 40℃) on the bacterial growth as well as CPF degradation rate by GC analysis were studied. Under the influence of different degrees of pH, a difference was observed in the number of metabolic products, as well as different proportions of some similar compounds in different media.