Optimizing conditions for carbofuran degrading isolates: a pathway to sustainable bioremediation in agricultural settings

Agriculture, driven by the escalating global demand for food, heavily relies on pesticides to ensure high yields and pest-free produce. The carbamate group of pesticides, including the widely used carbofuran, presents advantages such as low retention, high efficacy, and broad application. However, the associated health concerns categorize these pesticides as hidden threats. In response, biological remediation emerges as a more cost-efficient and environmentally friendly alternative to chemical or physical approaches. Our prior investigation identified 17 highly potential carbofuran degraders, forming the basis for this research. The focus lies on optimizing the isolates’ growth conditions, exploring temperatures (30 °C and 37 °C) and pH levels (7 and 9) in Bushnell Haas Agar. It was observed that all four pesticide doses (250, 500, 750, and 1000 mg/L) in Bushnell Haas Agar medium were supported by the majority of isolates at 30 °C and pH 9, whereas 750 and 1000 mg/L were favored at pH 7 (30 °C) and at both pH 7 and 9 (37 °C). Despite limited biofilm-forming ability rendered due to presence of <i>omp</i>A along with or with not <i>bap</i> gene, the isolates’ extracellular polymeric substance (EPS) composition indicated a polymeric nature. Also 13 of the isolates’ EPS production accelerates at 250 mg/L pesticide concentration. Metabolic pathway analyses revealed a preference for hydrolytic degradation, while molecular examinations confirmed the presence of plasmid and the absence of specific genes <i>mcd</i> and <i>ceh</i>A responsible for carbamate – hydrolase on the chromosome. Concern is raised by the presence of colistin and tetracycline resistant genes (mcr2 (47.05%), tetA (29.41%), and qnrs (23.53%) in the genomic content of some isolates, in addition to ESBL resistance genes found in varying frequencies, such as blaIMP3 (5.89%), blaVIM (70.59%), blaKPC (88.25%), blaOXA-1 (11.76%), bla-SHV (23.53%) &amp; blaOXA1 (11.76%), bla-CTMX15 (17.65%), necessitating alternative mechanisms. The findings demonstrate the isolates’ dual function as repositories of antibiotic resistance and prospective bioremediation agents, requiring careful handling and application. Developing safe and efficient bioremediation systems will need addressing resistance issues while maximizing degrading efficiency.