Comparative genomics reveals the evidence of aromatic hydrocarbons degradation potential in genus Roseovarius in marine environment

Aromatic compounds are eco-toxic organic pollutants widely distributed in the marine environment, and microbes of the genus Roseovarius have demonstrated high potential for bioremediation and degradation of aromatic compounds. However, rare comprehensive comparative genomic studies of the genus Roseovarius on their diversity and aromatic degrading functions are available. In this work, the whole genome of phenanthrene-degrading strain Roseovarius sp. SCSIO 43702 was sequenced and comparatively analyzed with other 44 isolated Roseovarius strains. We have detected a weak significant (ANOSIM, R = 0.3804, p = 0.01) between the phylogenetic clades and the geographic source, and found a complete phenanthrene metabolic pathway presented in most Roseovarius strains. Further, nine investigated Roseovarius strains were selected for the phenanthrene biodegradation assay, and eight marine originated strains exhibited significant higher the degrading ability (T-test, p < 0.05) than control group. Collectively, these results showed the environmental adaptation and aromatic degradation potential of the genus Roseovarius at the genomic and phenotypic levels, and provided references to evaluate applicable prospects of Roseovarius strains in aromatic bioremediation of the marine environment.