title: [Assimilation of carbon dioxide and oxidation of methane in various zones of the Rainbow hyperthermophilic field zones].
abstract: Rates of carbon dioxide assimilation and methane oxidation were determined in various zones of the Rainbow Hydrothermal Field (36 degrees N) of the Mid-Atlantic Ridge. In the plume above the hydrothermal field, anomalously high methane content was recorded; the microbial population density (up to 10(5) cells/ml) was an order of magnitude higher than the background values; and the CO2 assimilation rate varied from 0.01 to 1.1 micrograms C/(1 day). Based on the data on CO2 assimilation, the production of organic carbon due to bacterial chemosynthesis in the plume was calculated to be 930 kg/day or 340 tons/year (about 29% of the organic carbon production in the photic zone). In the black smoke above active smokers, the microbial population density was as high as 10(6) cells/ml; the rate of CO2 assimilation made up 5-10 micrograms C/(1 day); the methane oxidation rate varied from 0.15 to 12.7 mu/(1 day); and the methane concentration ranged from 1.05 to 70.6 mu/l. In bottom sediments enriched with sulfides, the rate of CO2 assimilation was at least an order of magnitude higher than in oxidized metal-bearing sediments. At the base of an active construction site, whitish sediment was found, which was characterized by a methane high content (92 mu/dm3) and a high rate of oxidation (1.7 mu/(dm3 day)).
authors.affiliation: Institute of Microbiology, Russian Academy of Sciences, pr. 60-letiya Oktyabrya 7, k. 2, Moscow, 117811 Russia.
authors.forename: N V
authors.initials: NV
authors.lastname: Pimenov
authors.forename: A Iu
authors.initials: AIu
authors.lastname: Lein
authors.forename: A M
authors.initials: AM
authors.lastname: Sagalevich
authors.forename: M V
authors.initials: MV
authors.lastname: Ivanov
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D002245:Carbon Dioxide; D008697:Methane
vernacular_title: Assimiliatsiia uglekisloty i okislenie metana v razlichnykh zonakh gidrotermal'nogo polia réĭnbou.