Taxonomically and functionally diverse microbial communities in deep crystalline rocks of the Fennoscandian shield.
Microbial life in the nutrient-limited and low-permeability continental crystalline crust is abundant but remains relatively unexplored. Using high-throughput sequencing to assess the 16S rRNA gene diversity, we found diverse bacterial and archaeal communities along a 2516-m-deep drill hole in continental crystalline crust in Outokumpu, Finland. These communities varied at different sampling depths in response to prevailing lithology and hydrogeochemistry. Further analysis by shotgun metagenomic sequencing revealed variable carbon and nutrient utilization strategies as well as specific functional and physiological adaptations uniquely associated with specific environmental conditions. Altogether, our results show that predominant geological and hydrogeochemical conditions, including the existence and connectivity of fracture systems and the low amounts of available energy, have a key role in controlling microbial ecology and evolution in the nutrient and energy-poor deep crustal biosphere.
VTT Technical Research Centre of Finland, Espoo, Finland.
Mari
M
Nyyssönen
Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
Jenni
J
Hultman
Geological Survey of Finland, Espoo, Finland.
Lasse
L
Ahonen
Geological Survey of Finland, Espoo, Finland.
Ilmo
I
Kukkonen
Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
Lars
L
Paulin
Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
Pia
P
Laine
VTT Technical Research Centre of Finland, Espoo, Finland.
Merja
M
Itävaara
Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
Petri
P
Auvinen
D000222:Adaptation, Physiological / Q000235:genetics; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000502:physiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000821:virology; D018407:Bacterial Physiological Phenomena; D001435:Bacteriophages / Q000235:genetics; D044822:Biodiversity; D057486:Carbon Cycle; D005387:Finland; D005844:Geology; D056186:Metagenomics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014867:Water / Q000737:chemistry
D012336:RNA, Ribosomal, 16S; D012987:Soil; D014867:Water