Comparative Genomics of Rhamnolipid Synthesis and Monoaromatic Hydrocarbon Tolerance Genes in Environmental strains.

BACKGROUND

Bioremediation faces several compounds to recover oil spilled ecosystem. The BTEX (benzene, toluene, ethylbenzene, and xylene) are toxic hydrocarbons requiring efficient microbial degradation for bioremediation. can degrade hydrocarbons through emulsification ( genes) and tolerance ( genes). However, genomic organization of these systems in environmental strains remains unclear. This study aimed to investigate the and systems in six strains isolated from hydrocarbon-contaminated sites in Peru.

METHODS

Six strains were evaluated in this study. Each strain were able to degrade hydrocarbon and tolerate heavy metals. DNA extraction, sequencing, and quality-controlled assembly, functional genome annotation was performed using BAKTA. Comparative analysis included high-quality genomes from RefSeq, with ANI metrics. A phylogenetic tree was built from core gene alignment, revealed evolutionary connections and was visualized with iTOL.

RESULTS

The assembled genomes ranged from 5.6 to 6.0 Mbp with ~66% GC content. All the strains were confirmed as by ANI; placing them within Clade 1 alongside environmental and clinical strains. Pangenome analysis identified 3,544 core genes and a diverse accessory genome. All strains had genes in a conserved 3'-5' orientation. Most of them contained duplicated gene, except C1BHIC5 strain. However, varied in position and orientation, it was often near , with C1BHIC5 also displaying an exception in orientation.100% of strains presented system, associated with toluene tolerance, with two copies of , , and genes arranged with high synteny but variable orientations. In comparison to , where genes are positioned between and with an additional toluene tolerance gene ( ).

CONCLUSIONS

In conclusion, the presence of the genes and the BTEX tolerance genes in all of the analyzed strains allowed us to understand the great ability of to survive in polluted environments.