Parallel artificial and biological electric circuits power petroleum decontamination: The case of snorkel and cable bacteria

TY - JOUR

T1 - Parallel artificial and biological electric circuits power petroleum decontamination

T2 - The case of snorkel and cable bacteria

AU - Marzocchi, Ugo

AU - Palma, Enza

AU - Rossetti, Simona

AU - Aulenta, Federico

AU - Scoma, Alberto

PY - 2020/4

Y1 - 2020/4

N2 - Degradation of petroleum hydrocarbons (HC) in sediments is often limited by the availability of electron acceptors. By allowing long-distance electron transport (LDET) between anoxic sediments and oxic overlying water, bioelectrochemical snorkels may stimulate the regeneration of sulphate in the anoxic sediment thereby accelerating petroleum HC degradation. Cable bacteria can also mediate LDET between anoxic and oxic sediment layers and thus theoretically stimulate petroleum HC degradation. Here, we quantitatively assessed the impact of cable bacteria and snorkels on the degradation of alkanes in marine sediment from Aarhus Bay (Denmark). After seven weeks, cable bacteria and snorkels accelerated alkanes degradation by +24 and +25%, respectively, compared to control sediment with no cable bacteria nor snorkel. The combination of snorkels and cable bacteria further enhanced alkanes degradation (+46%). Higher degradation rates were sustained by LDET-induced sulphide removal rather than, as initially hypothesized, sulphate regeneration. Cable bacteria are thus overlooked players in the self-healing capacity of crude-oil contaminated sediments, and may inspire novel remediation treatments upon hydrocarbon spillage.

AB - Degradation of petroleum hydrocarbons (HC) in sediments is often limited by the availability of electron acceptors. By allowing long-distance electron transport (LDET) between anoxic sediments and oxic overlying water, bioelectrochemical snorkels may stimulate the regeneration of sulphate in the anoxic sediment thereby accelerating petroleum HC degradation. Cable bacteria can also mediate LDET between anoxic and oxic sediment layers and thus theoretically stimulate petroleum HC degradation. Here, we quantitatively assessed the impact of cable bacteria and snorkels on the degradation of alkanes in marine sediment from Aarhus Bay (Denmark). After seven weeks, cable bacteria and snorkels accelerated alkanes degradation by +24 and +25%, respectively, compared to control sediment with no cable bacteria nor snorkel. The combination of snorkels and cable bacteria further enhanced alkanes degradation (+46%). Higher degradation rates were sustained by LDET-induced sulphide removal rather than, as initially hypothesized, sulphate regeneration. Cable bacteria are thus overlooked players in the self-healing capacity of crude-oil contaminated sediments, and may inspire novel remediation treatments upon hydrocarbon spillage.

KW - Cable bacteria

KW - Hydrocarbon

KW - Long-distance electron transport

KW - Remediation

KW - Sediment

KW - Snorkel

KW - GEN. NOV.

KW - CARBON

KW - SULFATE-REDUCING BACTERIUM

KW - SP-NOV.

KW - SULFIDE

KW - SULFUR-OXIDIZING CHEMOLITHOAUTOTROPH

KW - RECLASSIFICATION

KW - TRANSPORT

KW - MICROBIAL COMMUNITIES

KW - CELL

UR - http://www.scopus.com/inward/record.url?scp=85078679932&partnerID=8YFLogxK

U2 - 10.1016/j.watres.2020.115520

DO - 10.1016/j.watres.2020.115520

M3 - Journal article

C2 - 32018171

AN - SCOPUS:85078679932

SN - 0043-1354

VL - 173

JO - Water Research

JF - Water Research

M1 - 115520

ER -