Microbial communities in the deep Kurnub Group Nubian Sandstone and the overlying Judea Group Carbonate aquifers

Diverse microbes catalyze biogeochemical cycles in the terrestrial subsurface, yet the corresponding ecophysiology was only estimated in a limited number of subterrestrial, often shallow aquifers. Here, we detrained the productivity, diversity and functions of active microbial communities in the deep Kurnub Group Nubian Sandstone and the overlying Judea Group Carbonate aquifers (0.59 to 1.2 km below ground). Microbes are the key producers in these pristine oligotrophic aquifers that were recharged 10,000-620,000 years ago and contain fresh to brackish, suboxic to anoxic, often hot (37 to 59 C) water.