Stimulation of in vitro anaerobic oxidation of methane rate in a continuous high-pressure bioreactor.
Anaerobic oxidation of methane coupled to sulphate reduction (SR-AOM) prevents oceanic methane emissions and is considered as a major environmental process in the deep-sea sediments. To stimulate in vitro SR-AOM activity, we designed a (continuous) high-pressure bioreactor system. Fed-batch mode incubations showed that the elevated methane pressure stimulated SR-AOM activity: when the methane pressure increased from 1 to 4.5 to 8 MPa, the initial SR-AOM activity increased from 3.46 to 8.64 to 9.22 micromol sulphide production/g(dw)/day; the apparent affinity (K(m)) for methane was 37 mM. However, in each fed-batch mode incubation, there was an inhibitory effect observed after 2 days, probably due to the accumulation of sulphide and the increase of pH. When the reactor was operated in a continuous mode, the SR-AOM activity was constantly increasing within 18 days at both 1 and 8 MPa pressures.
Zhang
Yu
Y
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
Henriet
Jean-Pierre
JP
Bursens
Jeroen
J
Boon
Nico
N
D000693:Anaerobiosis; D019149:Bioreactors / Q000382:microbiology*; D008697:Methane / Q000378:metabolism*; D010084:Oxidation-Reduction; D011312:Pressure; D013440:Sulfides / Q000378:metabolism
D013440:Sulfides; D008697:Methane