HR: 0800h
AN: V41B-1395    [Abstracts]
TI: Quantitative Population Analysis of Some Groups of Epsilon-Proteobacteria, Using in situ Growth Chamber Samples From Hydrothermal Vents in the South Mariana
AU: * Miyako, C
EM: c.miyako@aist.go.jp
AF: Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8566 Japan
AU: Higashi, Y
EM: y-higashi@aist.go.jp
AF: Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8566 Japan
AU: Maruyama, A
EM: maruyama-aki@aist.go.jp
AF: Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, 305-8566 Japan
AB: To reveal deep-sea hydrothermal microbial ecosystems, we have developed and applied several new sampling systems, e.g., in situ filter samplers and in situ growth chambers. The later enables to incubate and accumulate microbes inside a hydrothermal vent with complex physico-chemical gradients naturally created in a vent flow. Using this system, we have found several novel phylotypes of microbes in the Suiyo Seamount. Among them, two novel groups of epsilon-Proteobacteria (SSSV-BE1 and SSSV-BE2; Higashi et al. FEMS-ME 2004) were assumed to originate from sub-vent fields, mainly at the borehole SH-APSK05. Some of the known epsilon groups, i.e., CorreOs Groups D (the hydrothermal vent type) and Group B (the microbial mat type), were also detected in the same samples. Afterwards, we have further improved in situ growth chambers larger to gain enough amounts of microbial RNA samples for quantitative population analyses. A new chamber system named column-II type was then applied to a natural vent at Fryer site in the Mariana Trough, with temperatures of venting fluids beyond 109 C. Through the 16S rRNA gene clone library analysis, members of the above epsilon-Proteobacteria groups were frequently found in this column-II chamber sample, as well as the Suiyo Seamout samples. So, we tried to estimate population sizes of these epsilons by a quantitative fluorescent dot-blot hybridization (FDBH) technique. First, we newly designed two novel oligonucleotide probes specific to members of the groups D (26 mer) and SSSV-BE1 (23 mer), in which the stringency was checked using soft wares from Ribosomal Database Project II and DDBJ. Total RNA samples, after extracted and purified from the chamber samples, were applied to a nylon membrane filter and hybridized with these two specific probes, as well as Eubacteria, Universal, and some sub-domain/group-specific probes. After the hybridization, resulting fluorescence intensities were quantified, averaged, and compared each other, and then the target microbial population was calculated. Finally, we estimated the relative abundance of these epsilon-Proteobacteria groups in the total Bacteria, and the results implied that more SSSV-BE and group D exist as it goes to the deeper sub-vent. Further examinations of the population, and of whether this phenomenon can be observed commonly such as from the Suiyo Seamount samples, are carried out at the moment.
DE: 4832 Hydrothermal systems
DE: 4840 Microbiology
DE: 4894 Instruments and techniques
DE: 4803 Bacteria
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting