Comparative genomics of ۹۱۹ microbial genomes of the order Oceanospirillales for oil hydrocarbon degradation

Oil pollution is a threat for the ocean ecosystem; negatively affecting the health of aquaticorganisms and humans. Biological remediation provides a sustainable approach for alleviating threatsof oil pollution on aquatic ecosystems and harnessing the ability of microbes for oil degradation in theocean ecosystem has a vast potential that still remains largely untapped[۱][۲][۳].Order Ocaenospirillales representatives are first responders to release of oil hydrocarbons, where theybloom due to their enzymatic profile enabling them to degrade oil hydrocarbons. Here, we present acomparative genomics study of the capability of Ocaenospirillales genomes for oil hydrocarbondegradation. Also, position of key hydrocarbon degradation genes in the core or accessory fraction ofthe pangenome was inspected to shed light on the flow of these genes among populations.A number of ۸۴۵ Ocaenospirillales genomes were collected from the National Center forBiotechnology Information and ۷۴ MAGs from oil contaminated sites were added to this dataset. Afterquality control, using CheckM, prodigal was used to predict genes and eggNOG-mapper were used forfunctional annotation. FastANI and motulizer were used For genome clustering. then pangenomeanalysis was done using the Bayesian approach of mOTUpan.py.Updated taxonomy based on ۱۲۰ single-copy gene markers show that members of the orderoceanospirillales are transferred to the five orders of Pseudomonadales, Enterobacterales,Xanthomonadales, HP۱۲, and Nevskiiales. ۷۰% of all families were rich in genes capable of degradingalkanes. Moreover, ۸۳% of genes involved in aliphatic hydrocarbons degradation were located in thecore fraction of the pangenomes, reiterating the fact that the flow if these genes is mainly vertical.However, genes responsible for breaking down aromatic compounds were mostly in the accessoryfraction of the pangenomes. highlighting that bacteria mainly acquired these capabilities throughhorizontal transfer in order to become more compatible with their environment.

کلیدواژه ها:

Oil hydrocarbons ، comparative genomics ، pangenome ، Core genome ، Accessory genome