Journal
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
Volume 71, Issue 8, Pages 4822-4832Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/AEM.71.8.4822-4832.2005
Keywords
-
Categories
Ask authors/readers for more resources
Stromatolites, organosedimentary structures formed by microbial activity, are found throughout the geological record and are important markers of biological history. More conspicuous in the past, stromatolites occur today in a few shallow marine environments, including Hamelin Pool in Shark Bay, Western Australia. Hamelin Pool stromatolites often have been considered contemporary analogs to ancient stromatolites, yet little is known about the microbial communities that build them. We used DNA-based molecular phylogenetic methods that do not require cultivation to study the microbial diversity of an irregular stromatolite and of the surface and interior of a domal stromatolite. To identify the constituents of the stromatolite communities, small subunit rRNA genes were amplified by PCR from community genomic DNA with universal primers, cloned, sequenced, and compared to known rRNA genes. The communities were highly diverse and novel. The average sequence identity of Hamelin Pool sequences compared to the >200,000 known rRNA sequences was only similar to 92%. Clone libraries were similar to 90% bacterial and similar to 10% archaeal, and eucaryotic rRNA genes were not detected in the libraries. The most abundant sequences were representative of novel proteobacteria (similar to 28%), planctomycetes (similar to 17%), and actinobacteria (similar to 14%). Sequences representative of cyanobacteria, long considered to dominate these communities, comprised <5% of clones. Approximately 10% of the sequences were most closely related to those of alpha-proteobacterial anoxygenic phototrophs. These results provide a framework for understanding the kinds of organisms that build contemporary stromatolites, their ecology, and their relevance to stromatolites preserved in the geological record.
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