Background: Polycyclic aromatic hydrocarbon contamination presents significant environmental challenges, requiring effective bioremediation solutions. Methods: Bacillus altitudinis DG4, isolated from the Damanganga River in Vapi, India, was investigated for its genomic characteristics and naphthalene degradation capabilities using whole genome sequencing and Gas Chromatography-Mass Spectrometry (GC–MS) analysis. Results: Genome sequencing revealed a 3,831,796 base pair genome with 4120 protein-coding sequences. Genome annotation identified genes involved in diverse metabolic pathways including xenobiotic degradation. Pan-genome analysis of 122 B. altitudinis genomes revealed 2403 core genes, 1588 accessory genes, and 40 unique genes in strain DG4. Naphthalene degradation experiments showed that strain DG4 exhibited the highest degradation efficiency (90.0%) among five isolates tested, despite a moderate growth rate. GC–MS analysis confirmed the metabolism of naphthalene and formation of key intermediates, including 1-naphthalenol, 1,8-naphthalic anhydride, 1-acenaphthanone, and benzoic acid, suggesting a specific degradation pathway. Conclusion: The presence of genes associated with degradation pathways and the experimental validation of naphthalene degradation highlight the strong bioremoval potential of B. altitudinis DG4 for naphthalene-contaminated environments. These findings contribute to understanding microbial degradation mechanisms and support the development of effective bioremediation strategies for polycyclic aromatic hydrocarbon pollution. Graphical

The Damanganga River faces severe pollution from industrial effluents and sewage, impacting its ecological health. The study aimed to analyze the current water quality status at the proposed conventional barrage site across the river between Silvassa, Vapi and Daman in India. Water samples were collected from three sites along the river during different seasons and analyzed for physicochemical parameters like TDS, COD, BOD, nutrients, fecal coliforms, heavy metals, etc. as per standard methods. Principal component analysis (PCA) was done. GCMS profiling of organics was also carried out. Several parameters exceeded the desired limits. TDS, BOD, fecal coliforms were very high indicating organic pollution and sewage contamination. Dissolved oxygen was deficient at some sites. Cadmium, copper and iron exceeded limits due to industrial releases containing these metals. PCA showed organic pollution as the major degrading factor for water quality followed by industrial contamination. GCMS analysis revealed hazardous organics like petrochemicals, fatty acids, solvents, pesticides and aromatic pollutants at varying levels along the river’s course demonstrating pollution from oil spillages, industrial effluents and agricultural runoff. The findings confirm severe deterioration in the Damanganga's water quality from inadequately treated sewage and industrial discharges posing environmental and health risks. Stringent regulations, proper wastewater treatment, runoff control and regular monitoring are vital to improve the river's condition