Genome-Centric Metatranscriptomics Reveals Multiple Co-occurring Routes for Hydrocarbon Degradation in Chronically Contaminated Marine Microbial Mats

Abstract

Long-term hydrocarbon pollution is a devious threat to aquatic and marine ecosystems. However, microbial responses to chronic pollution remain poorly understood. Combining genome-centric metagenomic and metatranscriptomic analyses of microbial mat samples that experienced chronic hydrocarbon pollution for more than 80 years, we analyzed the transcriptomic activity of alkane and aromatic hydrocarbon degradation pathways at the population level. Consistent with the fluctuating and stratified redox conditions of the habitat, both aerobic and anaerobic hydrocarbon degradation pathways were expressed by taxonomically and metabolically contrasted lineages including members of Bacteroidiales, Desulfobacteraceae, Pseudomonadales; Alcanivoraceae and Halieaceae populations with (photo)-heterotrophic, sulfur-and organohalide-based metabolisms, providing evidence for the co-occurrence and activity of aerobic and anaerobic hydrocarbon degradation pathways in shallow marine microbial mats. In addition, our results suggest that aerobic alkane degradation in long-term pollution involved bacterial families that are naturally widely distributed in marine habitats, but hydrocarbon concentration and composition were found to be a strong structuring factor of their intrafamily diversity and transcriptomic activities.

Maximizing the Impact of Research Featuring Nucleic-Acid Sequencing Methods in Environmental Science & Technology and Environmental Science & Technology Letters

“…Nucleic-acid sequencing tools are critical in the field of environmental science and technology. They have provided insights into the role of microorganisms in wastewater treatment processes, , drinking water systems, and consortia capable of degrading chemical pollutants. , They have provided important insights into anthropogenic impacts on aquatic food webs and the response of model organisms to chemical exposures …”