T.R. Kulp J.S. Blum S.E. Hoeft S. Baesman L.G. Miller J.F. Stolz R.S. Oremland 2005 Searles Lake is a salt-saturated, alkaline brine unusually rich in the toxic element arsenic. Arsenic speciation changed from arsenate [As(V)] to arsenite [As(III)] with sediment depth. Incubated anoxic sediment slurries displayed dissimilatory As(V)-reductase activity that was markedly stimulated by H2 or sulfide, whereas aerobic slurries had rapid As(III)-oxidase activity. An anaerobic, extremely haloalkaliphilic bacterium was isolated from the sediment that grew via As(V) respiration, using either lactate or sulfide as its electron donor. Hence, a full biogeochemical cycle of arsenic occurs in Searles Lake, driven in part by inorganic electron donors. application/pdf 10.1126/science.1110832 en AAAS Microbiology: A microbial arsenic cycle in a salt-saturated, extreme environment article