Connectivity to the surface determines diversity patterns in subsurface aquifers of the Fennoscandian shield
2016 (English)In: The ISME Journal, ISSN 1751-7362, E-ISSN 1751-7370Article in journal (Refereed) Epub ahead of printText
Little research has been conducted on microbial diversity deep under the Earth/'s surface. In this study, the microbial communities of three deep terrestrial subsurface aquifers were investigated. Temporal community data over 6 years revealed that the phylogenetic structure and community dynamics were highly dependent on the degree of isolation from the earth surface biomes. The microbial community at the shallow site was the most dynamic and was dominated by the sulfur-oxidizing genera Sulfurovum or Sulfurimonas at all-time points. The microbial community in the meteoric water filled intermediate aquifer (water turnover approximately every 5 years) was less variable and was dominated by candidate phylum OD1. Metagenomic analysis of this water demonstrated the occurrence of key genes for nitrogen and carbon fixation, sulfate reduction, sulfide oxidation and fermentation. The deepest water mass (5000 year old waters) had the lowest taxon richness and surprisingly contained Cyanobacteria. The high relative abundance of phylogenetic groups associated with nitrogen and sulfur cycling, as well as fermentation implied that these processes were important in these systems. We conclude that the microbial community patterns appear to be shaped by the availability of energy and nutrient sources via connectivity to the surface or from deep geological processes.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:uu:diva-294186OAI: oai:DiVA.org:uu-294186DiVA: diva2:929189
Supplementary information available for this article at http://www.nature.com/ismej/journal/vaop/ncurrent/suppinfo/ismej201636s1.html2016-05-182016-05-182016-05-26Bibliographically approved