0000000000002777
AUTHOR
Bo Thamdrup
Interspecies interactions mediated by conductive minerals in the sediments of the ferruginous Lake La Cruz, Spain
AbstractLake La Cruz is considered a biogeochemical analogue to early Earth marine environments because its water column is depleted in sulfate, but rich in methane and iron, similar to conditions envisaged for much of the Precambrian. In this early Earth analogue environment, we show that conductive particles establish a tight metabolic coupling between electroactive microbial clades. We propose that mineral-based syntrophy is of potential relevance for the evolution of Earth’s earliest complex life forms. We show that the anoxic sediment of Lake La Cruz, which is rich in biogeochemically ‘reactive’ iron minerals, harbors known electroactive species such asGeobacterandMethanothrix,in addit…
Interspecies interactions mediated by conductive minerals in the sediments of the iron rich meromictic Lake La Cruz, Spain
espanolLa laguna de La Cruz puede considerarse como un analogo biogeoquimico de los ambientes marinos en la Tierra primitiva, porque su columna de agua, muy escasa en sulfato pero rica en metano y hierro, presenta condiciones similares a estos ambientes en el Precambrico. En este ambiente encontramos que particulas conductivas establecen un acoplamiento metabolico entre clados microbianos electroactivos. Demostraremos que el sedimento anoxico de la laguna de La Cruz, rico en minerales de hierro biogeoquimicamente “reactivos”, alberga conocidas especies electroactivas tales como Geobacter y Methanothrix, ademas de otros grupos microbianos que no han sido previamente asociados con un estilo d…
Nitrogen Loss from Pristine Carbonate-Rock Aquifers of the Hainich Critical Zone Exploratory (Germany) Is Primarily Driven by Chemolithoautotrophic Anammox Processes
Despite the high relevance of anaerobic ammonium oxidation (anammox) for nitrogen loss from marine systems, its relative importance compared to denitrification has less been studied in freshwater ecosystems, and our knowledge is especially scarce for groundwater. Surprisingly, phospholipid fatty acids (PLFA)-based studies identified zones with potentially active anammox bacteria within two superimposed pristine limestone aquifer assemblages of the Hainich Critical Zone Exploratory (CZE; Germany). We found anammox to contribute an estimated 83% to total nitrogen loss in suboxic groundwaters of these aquifer assemblages at rates of 3.5-4.7 nmol L -1 d -1, presumably favored over denitrificati…