Transient exposure to oxygen and nitrate reveals ecophysiology of intertidal microbial populations

Microbial communities of intertidal sediments play an important role inglobal chemical cycles. However, little is known about the majority ofmicrobial populations in this dynamic ecosystem, their metabolisms andfunctions, or their response to diurnal disturbances. We used bioreactorsto enrich for sulfate-reducers and fermenters, key players in thesesediments. We then mimicked tidal cycles and investigated the impacts ofoxygen and nitrate on the anaerobic communities. This approach enabled usto gain insights into the ecophysiology of key functional organisms, aswell as into so far uncultivated bacterial clades.