Diversity and Hydrocarbon-Degrading Potential of Deep-Sea Microbial Community from the Mid-Atlantic Ridge, South of the Azores (North Atlantic Ocean)

Abstract

Deep-sea sediments (DSS) are one of the largest biotopes on Earth and host a surprisingly diverse microbial community. The harsh conditions of this cold environment lower the rate of natural attenuation, allowing the petroleum pollutants to persist for a long time in deep marine sediments raising problematic environmental concerns. The present work aims to contribute to the study of DSS microbial resources as biotechnological tools for bioremediation of petroleum hydrocarbon polluted environments. Four deep-sea sediment samples were collected in the Mid-Atlantic Ridge, south of the Azores (North Atlantic Ocean). Their autochthonous microbial diversity was investigated by 16S rRNA metabarcoding analysis. In addition, a total of 26 deep-sea bacteria strains with the ability to utilize crude oil as their sole carbon and energy source were isolated from the DSS samples. Eight of them were selected for a novel hydrocarbonoclastic-bacterial consortium and their potential to degrade petroleum hydrocarbons was tested in a bioremediation experiment. Bioaugmentation treatments (with inoculum pre-grown either in sodium acetate or petroleum) showed an increase in degradation of the hydrocarbons comparatively to natural attenuation. Our results provide new insights into deep-ocean oil spill bioremediation by applying DSS hydrocarbon-degrading consortium in lab-scale microcosm to simulate an oil spill in natural seawater.

Bacterial Communities and Culturable Petroleum Hydrocarbon Degrading Bacteria in Marine Sediments in the Northeastern South China Sea

“…There were more low temperature petroleum hydrocarbon degrading strains isolated from S39 than from S02. Hydrocarbon degrading microorganisms were more abundant in the deep sea basin due to the accumulation of organic matter and low temperature (Tomasino et al, 2021).…”

“…Recent studies demonstrated there were plenty of hydrocarbon degrading bacteria in the Mariana Trench (Liu J. et al, 2019). Although several petroleum hydrocarbon degrading bacteria had been isolated from deep-sea sediments (Gao et al, 2015;Tomasino et al, 2021), the current research on their degradation potential was still limited.…”

Oil Biodegradation and Bioremediation in Cold Marine Environment

“…The effect of biostimulation on microbial community abundance, structure, dynamics, and the metabolic potential for oil hydrocarbon degradation in oil-contaminated Arctic seawater were studied by Nõlvak et al [ 6 ]. The second paper, by Tomasino and co-authors [ 7 ], addressed petroleum pollution in cold, deep marine sediments. Using the deep-sea sediment samples from the North Atlantic Ocean, they identified bacterial strains with the potential for the enhanced bioremediation of petroleum hydrocarbon-polluted sediments.…”