Pesticide contamination has become a major environmental concern with organophosphates such as chlorpyrifos emerging as major pollutants posing significant risks to both ecosystems and human health. Chlorpyrifos is widely used in agriculture to control pests, however due to its persistence, its accumulation in soils can lead to long-term environmental damage. The objective of this study was to isolate and characterize chlorpyrifos-degrading bacteria from a tobacco field exposed to intensive pesticide use in T & uuml;rkiye. To achieve this, a selective enrichment strategy was employed to promote the growth of chlorpyrifos-degrading microorganisms. Two distinct experimental setups were established to target both normally growing and slower-growing bacteria: the first involved a 4-week incubation with weekly subculturing as described in the literature, while the second applied an 8-week incubation with biweekly subculturing. At the end of the enrichment period, bacterial loads were compared between the two groups. Four of the nine bacterial isolates were obtained from the newly tested long-term setup. Among all isolates, members of the genus Pseudomonas exhibited the best adaptation to the prolonged enrichment conditions. Additionally, isolates belonging to the genera Klebsiella, Sphingobacterium, and Peribacillus were isolated from the normally growing group. Two isolates (AB4 & AB15), identified as Sphingobacterium thalpophilum, were determined to be novel chlorpyrifos degraders. This is the first reported study from T & uuml;rkiye focusing on the biodegradation of chlorpyrifos by native soil bacteria. The findings revealed that various ecological areas, constitute potential sources for new microbial metabolic processes and these bacterial strains can be used in bioremediation studies.

Chlorpyrifos contamination is a currently on-going issue with significant environmental impacts. As such, rapid and effective techniques that remove chlorpyrifos from the environment are urgently required. Here, a strain of Pseudomonas nitroreducens W-7 exhibited exceptional degradation ability towards both chlorpyrifos and its major metabolite 3,5,6-trichloro-2-pyridinol (TCP). W-7 can effectively reduce the toxicity of chlorpyrifos and TCP towards a variety of sensitive organisms through its superior degradation capacity. W-7 demonstrated efficient soil bioremediation by removing over 50 % of chlorpyrifos (25 mg/kg) from both sterile and non-sterile soils within 5 days, with significantly reduced half-lives. Additionally, 16S rDNA high-throughput sequencing of the soil revealed that the introduction of W-7 had no significant impact on the soil microbial community. A pivotal hydrolase Oph2876 containing conserved motif (HxHxDH) and a bimetallic catalytic center was identified from W-7. Oph2876 was a heat- and alkali-resistant enzyme with low sequence similarity (< 44 %) with other reported organophosphorus hydrolases, with a better substrate affinity for hydrolysis of chlorpyrifos to TCP. The molecular docking and site-directed mutagenesis studies indicated that the amino acid residues Asp235, His214, and His282, which were associated with the conserved sequence HxHxDH, were crucial for the activity of Oph2876. These findings contribute to a better understanding of the biodegradation mechanism of chlorpyrifos and present useful agents for the development of effective chlorpyrifos bioremediation strategies.

Since India is one of the most populated countries in the world, there is a constant increase in the demand for food supply. To cater to the increased demand, the farmers use agrochemicals for crop protection and to enhance crop yield. Prolonged use of these agrochemicals, contaminates the groundwater, soil, and air, causing damage to our ecosystem and having adverse effects on human health. The present study reports the one-pot synthesis of graphene-CdS (GC) nanocomposites by a facile thermal decomposition approach. Thermal decomposition is an easy and cost-effective technique. It's a facile and more efficient method than other methods. The synthesized graphene-CdS nanocomposites were characterized using XRD, FT-IR spectroscopy, Diffuse Reflectance Spectroscopy, RAMAN spectroscopy, and FE-SEM analysis. The potential of GC nanocomposites has been explored as an efficient photocatalyst for the degradation of chlorpyrifos (CPY) in an aqueous solution. It was observed that the nanocomposites exhibit 89 % degradation efficiency in 90 minutes compared to the pristine CdS and Graphene. A detailed investigation of the degradation pathway and scavenger studies were also conducted. The Graphene-CdS hold scope and potential to be explored as an effective photocatalyst for the mineralization of agrochemicals. A novel Graphene/CdS nanocomposite synthesized via a thermal decomposition approach is used for the degradation of hazardous agrochemical, chlorpyrifos via, photocatalysis technique. The nanocomposite exhibits an excellent efficiency (89.9 %) for the removal of chloropyrifos.**image