Comparative study on ZnSe nanoparticles and biosurfactant for enhanced anthracene biodegradation

Polycyclic aromatic hydrocarbons (PAHs) such as anthracene persist in the ecosystem due to their low solubility, toxicity, and resistance to microbial attack, posing serious environmental and health risks. Current remediation approaches are often limited by poor degradation efficiency and incomplete mineralization. Here, we present a nano bioremediation strategy that couples Zinc Selenium (ZnSe) nanoparticles with biosurfactant-assisted microbial degradation to enhance anthracene removal. In this study, enrichment culture technique was performed to isolate potential strains, and it was identified as Dyadobacter endophyticus KSKT01 (accession number-PP422395) and Pseudomonas otitidis KKT09 (accession number-PP563796). The biosurfactants were isolated and characterized using FTIR and GC-MS, and it was identified as lipopeptides. The nanoparticles were synthesized and structurally characterized by a UV-Visible spectrophotometer, FTIR, FE-SEM, HR-TEM, EDX, AFM, and XRD. ZnSe exhibited an absorbance peak at 200 nm in the UV spectrum. The FTIR spectra showed possible functional groups associated with biomolecules (alkyne, alkene, and nitro compounds), FE-SEM and HR-TEM demonstrated that ZnSe nanoparticles were spherical in shape with a size range of 200 nm, and AFM also expressed a spherical form of the synthesized ZnSe NPs. XRD showed a crystalline size of 55.5 nm, and the element composition of ZnSe (Zn-53.2% and Se-46.8%) was analyzed by EDX. The obtained results expressed that ZnSe is stable and crystalline, which facilitated electron transfer and microbial interaction. Comparative degradation assays revealed that the combined nanoparticle, biosurfactant, and microbial consortium achieved 98% anthracene degradation in 14 days (50 mg/L). The Gas chromatography mass spectroscopy analysis confirmed the transformation of anthracene into less toxic intermediates such as naphthoic acid and salicylic acid via dioxygenase-mediated pathways. Our findings establish nanobioremediation as a promising platform for sustainable cleanup and provide mechanistic insight for anthracene degradation.