Archaeal diversity in waters from deep South African gold mines

A culture-independent molecular analysis of archaeal communities in waters collected from deep South African gold mines was performed by performing a PCR-mediated terminal restriction fragment length polymorphism (T-RFLP) ana lysis of rRNA genes (rDNA) in conjunction with a sequencing analysis of arc haeal rDNA clone libraries. The water samples used represented various envi ronments, including deep fissure water, mine service water, and water from an overlying dolomite aquifer. T-RFLP analysis revealed that the ribotype d istribution of archaea varied with the source of water. The archaeal commun ities in the deep gold mine environments exhibited great phylogenetic diver sity; the majority of the members were most closely related to uncultivated species. Some archaeal rDNA clones obtained from mine service water and do lomite aquifer water samples were most closely related to environmental rDN A clones from surface soil (soil clones) and marine environments (marine gr oup I [MGI]). Other clones exhibited intermediate phylogenetic affiliation between soil clones and MGI in the Crenarchaeota. Fissure water samples, de rived from active or dormant geothermal environments, yielded archaeal sequ ences that exhibited novel phylogeny, including a novel lineage of Euryarch aeota. These results suggest that deep South African gold mines harbor nove l archaeal communities distinct from those observed in other environments. Based on the phylogenetic analysis of archaeal strains and rDNA clones, inc luding the newly discovered archaeal rDNA clones, the evolutionary relation ship and the phylogenetic organization of the domain Archaea are reevaluate d.