Whole genome shotgun sequencing of POPs degrading bacterial community dwelling tannery effluents and petrol contaminated soil

Abstract

The present study involved identification of genes which are present in the genome of native bacteria to make them effective tools for bioremediation of persistent organic pollutants (POPs). During this study, forty-one POPs (naphthalene, toluene and petrol) metabolizing bacteria were isolated from tannery effluents and petrol contaminated soil samples by successive enrichment culturing. The taxonomic diversity and gene repertoire conferring POPs degradation ability to the isolated bacterial community were studied through whole genome shotgun sequencing of DNA consortium. The DNA consortium contained equimolar concentration of DNA extracted from each bacterial isolate using organic method. To add a double layer of confirmation the established DNA consortium was subjected to 16S rRNA metagenome sequencing and whole genome shotgun sequencing analysis. Biodiversity analysis revealed that the consortium was composed of phyla Firmicutes (80 %), Proteobacteria (12 %) and Actinobacteria (5%). Genera found included Bacillus (45 %), Burkholderia (25 %), Brevibacillus (9%) and Geobacillus (4%). Functional profiling of consortium helped us to identify genes associated with degradation pathways of a variety of organic compounds including toluene, naphthalene, caprolactam, benzoate, aminobenzoate, xylene, 4-hydroxyphenyl acetic acid, biphenyl, anthracene, aminobenzoate, chlorocyclohexane, chlorobenzene, n-phenylalkanoic acid, phenylpropanoid, salicylate, gentisate, central meta cleavage of aromatic compounds, cinnamic acid, catechol and procatechuate branch of β-ketoadipate pathway, phenyl-acetyl CoA and homogentisate catabolic pathway. The information thus generated has ensured not only biodegradation potential but also revealed many possible future applications of the isolated bacteria.