AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Inagaki, F.
Right arrow Articles by Horikoshi, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Inagaki, F.
Right arrow Articles by Horikoshi, K.
Agricola
Right arrow Articles by Inagaki, F.
Right arrow Articles by Horikoshi, K.
Applied and Environmental Microbiology, December 2004, p. 7445-7455, Vol. 70, No. 12
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.12.7445-7455.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Characterization of C1-Metabolizing Prokaryotic Communities in Methane Seep Habitats at the Kuroshima Knoll, Southern Ryukyu Arc, by Analyzing pmoA, mmoX, mxaF, mcrA, and 16S rRNA Genes

Fumio Inagaki,1* Urumu Tsunogai,2 Masae Suzuki,1 Ayako Kosaka,2 Hideaki Machiyama,3 Ken Takai,1 Takuro Nunoura,1 Kenneth H. Nealson,1,4 and Koki Horikoshi1

Subground Animalcule Retrieval (SUGAR) Project, Frontier Research System for Extremophiles,1 Deep-Sea Research Department, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka,3 Department of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan,2 Department of Earth Sciences, University of Southern California, Los Angeles, California4

Received 7 June 2004/ Accepted 27 July 2004

Samples from three submerged sites (MC, a core obtained in the methane seep area; MR, a reference core obtained at a distance from the methane seep; and HC, a gas-bubbling carbonate sample) at the Kuroshima Knoll in the southern Ryuku arc were analyzed to gain insight into the organisms present and the processes involved in this oxic-anoxic methane seep environment. 16S rRNA gene analyses by quantitative real-time PCR and clone library sequencing revealed that the MC core sediments contained abundant archaea (~34% of the total prokaryotes), including both mesophilic methanogens related to the genus Methanolobus and ANME-2 members of the Methanosarcinales, as well as members of the {delta}-Proteobacteria, suggesting that both anaerobic methane oxidation and methanogenesis occurred at this site. In addition, several functional genes connected with methane metabolism were analyzed by quantitative competitive-PCR, including the genes encoding particulate methane monooxygenase (pmoA), soluble methane monooxygenase (mmoX), methanol dehydrogenese (mxaF), and methyl coenzyme M reductase (mcrA). In the MC core sediments, the most abundant gene was mcrA (2.5 x 106 copies/g [wet weight]), while the pmoA gene of the type I methanotrophs (5.9 x 106 copies/g [wet weight]) was most abundant at the surface of the MC core. These results indicate that there is a very complex environment in which methane production, anaerobic methane oxidation, and aerobic methane oxidation all occur in close proximity. The HC carbonate site was rich in {gamma}-Proteobacteria and had a high copy number of mxaF (7.1 x 106 copies/g [wet weight]) and a much lower copy number of the pmoA gene (3.2 x 102 copies/g [wet weight]). The mmoX gene was never detected. In contrast, the reference core contained familiar sequences of marine sedimentary archaeal and bacterial groups but not groups specific to C1 metabolism. Geochemical characterization of the amounts and isotopic composition of pore water methane and sulfate strongly supported the notion that in this zone both aerobic methane oxidation and anaerobic methane oxidation, as well as methanogenesis, occur.


* Corresponding author. Mailing address: SUGAR Project, Frontier Research System for Extremophiles, JAMSTEC, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan. Phone: 81-468-67-9687. Fax: 81-468-67-9715. E-mail: inagaki{at}jamstec.go.jp.


Applied and Environmental Microbiology, December 2004, p. 7445-7455, Vol. 70, No. 12
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.12.7445-7455.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 2004 by the American Society for Microbiology. All rights reserved.