Selection of Biocarriers for Immobilization of a Sediment-Derived Bacterial Consortium Capable of Degrading Chlorpyrifos

Chlorpyrifos is a widely used organophosphate insecticide known for its high environmental persistence, raising concerns about its potential toxicity to both ecosystems and human health. This study focused on the biodegradation of chlorpyrifos using an immobilized consortium (Stenotrophomonas maltophilia strain IR94, Achromobacter xylosoxidans strain DN-06, Staphylococcus xylosus strain FFCShyA2, Staphylococcus arlettae strain P2, and Pseudomonas sp. strain SEH-7-A-V-1) isolated from a pesticide-contaminated site. The objective was also to identify an optimal biocarrier for immobilization. Various low-cost, eco‑friendly, and nontoxic agricultural and natural materials, including Coir pith, sugarcane bagasse (SCB), treated sugarcane bagasse (TSCB), banana stem (BS), treated banana stem (TBS), and Clay ball, were evaluated as immobilization matrices. FTIR analysis revealed that Coir pith‑immobilized bacterial consortium demonstrated more pronounced hydrolytic degradation activity compared to other carriers. The GCMS analysis proved that Coir pith‑immobilized bacterial consortium could degrade chlorpyrifos by 77% within 14 days. These findings highlight the strong potential of using agricultural waste-based matrices for cell immobilization, offering an effective and sustainable strategy for chlorpyrifos bioremediation in contaminated ecosystems.