Enriched bacterial community efficiently degrade polycyclic aromatic hydrocarbons in soil ecosystem: Insights from a mesocosms study

The comprehensive study on PAHs bioremediation together with microbial communities and their functional potential analysis is limited. PAHs biodegradation through mesocosm studies using polluted sediment from Alang-Sosiya ship breaking yard was performed to compare the impact of 3 different bioremediation approaches (natural attenuation, combined treatment of bioaugmentation-biostimulation using enriched consortia and chemical fertilizers and combined treatment using enriched consortia and organic manures). The highest degradation of naphthalene, phenanthrene, fluoranthene, pyrene and total PAHs after 60d of incubation were 94.3%, 88.9%, 59.2%, 60.7% and 76.0%, respectively in bioaugmented-biostimulated mesocosms using eight consortia and chemical fertilizers. Microbial community structure analysis indicated that combined treatments of bioaugmentation-biostimulation were able to replace the native microflora with PAHs degraders. Proteobacteria and Firmicutes phyla were dominant in all mesocosms. Chelatococcus genus was absent as native microflora in natural attenuation treatment, which was dominant in bioaugmented-biostimulated mesocosms. The functional potential of microbial communities was estimated using the PICRUSt. [Display omitted] •Mixture of four PAHs degradation was studied in polluted sediment mesocosms.•Systematically studied applicability of multiple enriched bacterial consortia in bioaugmentation.•Bioaugmentation & biostimulation induced changes in microbial community structure.•Microbial associations during degradation were explored through network analysis.•Functional prediction indicated PAHs degradation by multiple pathways concurrently.