AUTHOR=Oswald Kirsten , Jegge Corinne , Tischer Jana , Berg Jasmine , Brand Andreas , Miracle MarĂa R. , Soria Xavier , Vicente Eduardo , Lehmann Moritz F. , Zopfi Jakob , Schubert Carsten J. TITLE=Methanotrophy under Versatile Conditions in the Water Column of the Ferruginous Meromictic Lake La Cruz (Spain) JOURNAL=Frontiers in Microbiology VOLUME=7 YEAR=2016 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01762 DOI=10.3389/fmicb.2016.01762 ISSN=1664-302X ABSTRACT=
Lakes represent a considerable natural source of methane to the atmosphere compared to their small global surface area. Methanotrophs in sediments and in the water column largely control methane fluxes from these systems, yet the diversity, electron accepting capacity, and nutrient requirements of these microorganisms have only been partially identified. Here, we investigated the role of electron acceptors alternative to oxygen and sulfate in microbial methane oxidation at the oxycline and in anoxic waters of the ferruginous meromictic Lake La Cruz, Spain. Active methane turnover in a zone extending well below the oxycline was evidenced by stable carbon isotope-based rate measurements. We observed a strong methane oxidation potential throughout the anoxic water column, which did not vary substantially from that at the oxic/anoxic interface. Both in the redox-transition and anoxic zones, only aerobic methane-oxidizing bacteria (MOB) were detected by fluorescence