Genomic and biodegradation potential of Bacillus altitudinis DG4 for naphthalene removal from contaminated environments

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.