TY - JOUR
T1 - Diversity and functionality of archaeal, bacterial and fungal communities in deep Archaean bedrock groundwater
AU - Purkamo, Lotta
AU - Kietäväinen, Riikka
AU - Miettinen, Hanna
AU - Sohlberg, Elina
AU - Kukkonen, Ilmo
AU - Itävaara, Merja
AU - Bomberg, Malin
PY - 2018/6
Y1 - 2018/6
N2 - The diversity and metabolic functions of deep subsurface ecosystems remain relatively unexplored. Microbial communities in previously studied deep subsurface sites of the Fennoscandian Shield are distinctive to each site. Thus, we hypothesized that the microbial communities of the deep Archaean bedrock fracture aquifer in Romuvaara, northern Finland, differ both in community composition and metabolic functionality from the other sites in the Fennoscandian Shield. We characterized the composition, functionality and substrate preferences of the microbial communities at different depths in a 600 m deep borehole. In contrast to other Fennoscandian deep biosphere communities studied to date, iron-oxidizing Gallionella dominated the bacterial communities, while methanogenic and ammonia-oxidizing archaea were the most prominent archaea, and a diverse fungal community was also detected. Potential for methane cycling and sulfate and nitrate reduction was confirmed by detection of the functional genes of these metabolic pathways. Organotrophs were less abundant, although carbohydrates were the most preferred of the tested substrates. The microbial communities shared features with those detected from other deep groundwaters with similar geochemistry, but the majority of taxa distinctive to Romuvaara are different from the taxa previously detected in saline deep groundwater in the Fennoscandian Shield, most likely because of the differences in water chemistry.
AB - The diversity and metabolic functions of deep subsurface ecosystems remain relatively unexplored. Microbial communities in previously studied deep subsurface sites of the Fennoscandian Shield are distinctive to each site. Thus, we hypothesized that the microbial communities of the deep Archaean bedrock fracture aquifer in Romuvaara, northern Finland, differ both in community composition and metabolic functionality from the other sites in the Fennoscandian Shield. We characterized the composition, functionality and substrate preferences of the microbial communities at different depths in a 600 m deep borehole. In contrast to other Fennoscandian deep biosphere communities studied to date, iron-oxidizing Gallionella dominated the bacterial communities, while methanogenic and ammonia-oxidizing archaea were the most prominent archaea, and a diverse fungal community was also detected. Potential for methane cycling and sulfate and nitrate reduction was confirmed by detection of the functional genes of these metabolic pathways. Organotrophs were less abundant, although carbohydrates were the most preferred of the tested substrates. The microbial communities shared features with those detected from other deep groundwaters with similar geochemistry, but the majority of taxa distinctive to Romuvaara are different from the taxa previously detected in saline deep groundwater in the Fennoscandian Shield, most likely because of the differences in water chemistry.
KW - deep continental biosphere
KW - Fennoscandian Shield
KW - microbial diversity
KW - functional genes
KW - qPCR
UR - http://www.scopus.com/inward/record.url?scp=85054960671&partnerID=8YFLogxK
U2 - 10.1093/femsec/fiy116
DO - 10.1093/femsec/fiy116
M3 - Article
VL - 94
JO - FEMS Microbiology Ecology
JF - FEMS Microbiology Ecology
SN - 0168-6496
IS - 8
M1 - fiy116
ER -