Journal
MICROBIAL ECOLOGY
Volume 61, Issue 2, Pages 410-422Publisher
SPRINGER
DOI: 10.1007/s00248-010-9761-z
Keywords
-
Categories
Funding
- Swedish Nuclear Fuel and Waste Management Co.
- Swedish Research Council
Ask authors/readers for more resources
Six cores were drilled and retrieved from 186-m depth in the Aspo Hard Rock Laboratory (HRL) tunnel to investigate whether indigenous biofilms develop on fracture surfaces in groundwater-conducting aquifers in granitic rock. A clone library was constructed from fracture surface material (FSM), for community composition analysis. Quantitative polymerase chain reaction (qPCR) was applied to quantify gene copies using the 16S rRNA gene for domain Bacteria and the adenosine-phosphosulfate reductase gene (apsA) for sulfate-reducing bacteria (SRB). Results were compared with three groundwater systems with biofilms in laminar flow reactors (LFRs) at 450-m depth in the Aspo HRL. The total number of cells, counted microscopically, was approximately 2 Au 10(5) cells cm(-2) in the LFR systems, consistent with the obtained qPCR 16S rRNA gene copies. qPCR analysis reported similar to 1 Au 10(2) up to similar to 1 Au 10(4) gene copies cm(-2) on the FSM from the drill cores. In the FSM biofilms, 33% of the sequenced clones were related to the iron-reducing bacterium Stenotrophomonas maltophilia, while in the LFR biofilms, 41% of the sequenced clones were affiliated with the genera Desulfovibrio, Desulforhopalus, Desulfomicrobium, and Desulfobulbus. The community composition of the FSM biofilms differed from the drill water community, excluding drill water contamination. This work reports significant numbers of microorganisms on natural hard rock aquifer fracture surfaces with site-specific community compositions. The probability that biofilms are generally present in groundwater-conducting aquifers in deep granitic rock is consequently great.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available