Extended Data Fig. 1. Sampling site in the Guaymas Basin and microbial community in the original sediment.
a, Location of the Guaymas Basin in the Gulf of California. b, Bathymetry of the southern end of the Southern Trough of the Guaymas Basin with the location of the Cathedral Hill hydrothermal vent area. c, Sampling of the push core (4991-15) that was used for anoxic cultivations in an area densely covered by orange sulfur-oxidizing Beggiatoa mats. d, Depth-temperature profile in the sampling site. The temperature was measured using Alvin’s heatflow probe. Push cores reached about 30 cm into the sediment, where the temperature approached about 60 °C (sampling site photograph and temperature data courtesy of the Woods Hole Oceanographic Institution, from RV Atlantis cruise AT42-05). e, f Microbial community in the anoxic sediment slurry prepared from core 4991-15 before starting anoxic incubations based on 16S rRNA gene fragments recruited from the metagenome. e, On the domain level, archaea and bacteria each make up around 50%. f, Taxonomic groups on order level. For groups with unknown order assignment marked with *, the next known higher taxonomic levels are indicated. An ANME-1 group is abundant within the archaeal fraction while the bacterial fraction is very diverse.