Enhanced Hydrocarbons Biodegradation at Deep-Sea Hydrostatic Pressure with Microbial Electrochemical Snorkels

In anaerobic sediments, microbial degradation of petroleum hydrocarbons is limited by the rapid depletion electron acceptors (e.g., ferric oxide, sulfate) and accumulation toxic metabolites sulfide, following sulfate reduction). Deep-sea sediments are increasingly impacted oil contamination, elevated hydrostatic pressure (HP) they subjected to represents an additional limitation for metabolism. While use electrodes support electrobioremediation in oil-contaminated has been described, there no evidence on their applicability deep-sea sediments. Here, we tested a passive bioelectrochemical system named ”oil-spill snorkel” with two crude oils carrying different alkane contents (4 vs. 15%), at increased or ambient HP (10 0.1 MPa). Snorkels enhanced alkanes biodegradation both 10 MPa within only seven weeks, as compared nonconductive glass controls. Microprofiles anaerobic, contaminated indicated that snorkels kept sulfide concentration low titers. Bulk-sediment analysis confirmed oxidation largely regenerated sulfate. Hence, sole application could eliminate toxicity factor replenish spent acceptor HP. Both aspects crucial decontamination deep sea, remote environment featured metabolic activity.