TY  - JOUR
A1  - Lau, Maximilian P.
A1  - Hupfer, Michael
A1  - Grossart, Hans-Peter
T1  - Reduction-oxidation cycles of organic matter increase bacterial activity in the pelagic oxycline
JF  - Environmental microbiology reports
N2  - Dissolved organic matter (DOM) in aquatic ecosystems contains redox-active moieties, which are prone to oxidation and reduction reactions. Oxidized moieties feature reduction potentials E-h, so that the moieties may be used as terminal electron acceptors (TEAs) in microbial respiration with a thermodynamic energy yield between nitrate and sulfate reduction. Here, we study the response of pelagic freshwater bacteria to exposure to native DOM with varying availabilities of oxidized moieties and hence redox state. Our results show that the prevalence of oxidized DOM favors microbial production and growth in anoxic waters. Reduced DOM in stratified lakes may be oxidized when fluctuations of the oxycline expose DOM in previously anoxic water to epilimnetic oxygen. The resulting oxidized DOM may be rapidly used as TEAs in microbial respiration during subsequent periods of anoxia. We further investigate if the prevalence of these organic electron sinks in anaerobic incubations can induce changes in the microbial community. Our results reveal that DOM traversing transient redox interfaces selects for species that profit from such spatially confined and cyclically restored TEA reservoirs.
Y1  - 2017
U6  - https://doi.org/10.1111/1758-2229.12526
SN  - 1758-2229
VL  - 9
SP  - 257
EP  - 267
PB  - Wiley
CY  - Hoboken
ER  -