title: Microbiology of formation waters from the deep repository of liquid radioactive wastes Severnyi.
abstract: The presence, diversity, and geochemical activity of microorganisms in the Severnyi repository of liquid radioactive wastes were studied. Cultivable anaerobic denitrifiers, fermenters, sulfate-reducers, and methanogens were found in water samples from a depth of 162-405 m below sea level. Subsurface microorganisms produced methane from [2-(14)C]acetate and [(14)C]CO(2), formed hydrogen sulfide from Na(2) (35)SO(4), and reduced nitrate to dinitrogen in medium with acetate. The cell numbers of all studied groups of microorganisms and rates of anaerobic processes were higher in the zone of dispersion of radioactive wastes. Microbial communities present in the repository were able to utilise a wide range of organic and inorganic compounds and components of waste (acetate, nitrate, and sulfate) both aerobically and anaerobically. Bacterial production of gases may result in a local increase of the pressure in the repository and consequent discharge of wastes onto the surface. Microorganisms can indirectly decrease the mobility of radionuclides due to consumption of oxygen and production of sulfide, which favours deposition of metals. These results show the necessity of long-term microbiological and radiochemical monitoring of the repository.
authors.affiliation: Institute of Microbiology of Russian Academy of Sciences, Pr. 60-letiya Oktyabrya, 7/2, 117312 Moscow, Russia. nazina@inmi.host.ru, nazina@rambler.ru
authors.forename: Tamara N
authors.initials: TN
authors.lastname: Nazina
authors.forename: Inessa M
authors.initials: IM
authors.lastname: Kosareva
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Petrunyaka
authors.forename: Margarita K
authors.initials: MK
authors.lastname: Savushkina
authors.forename: Evgeniy G
authors.initials: EG
authors.lastname: Kudriavtsev
authors.forename: Valeriy A
authors.initials: VA
authors.lastname: Lebedev
authors.forename: Viktor D
authors.initials: VD
authors.lastname: Ahunov
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Revenko
authors.forename: Robert R
authors.initials: RR
authors.lastname: Khafizov
authors.forename: George A
authors.initials: GA
authors.lastname: Osipov
authors.forename: Sergey S
authors.initials: SS
authors.lastname: Belyaev
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Ivanov
mesh_terms: D001419:Bacteria / Q000302:isolation & purification* / Q000378:metabolism; D001673:Biodegradation, Environmental; D015169:Colony Count, Microbial; D004784:Environmental Monitoring; D011850:Radioactive Waste / Q000032:analysis*; D014867:Water / Q000032:analysis; D014871:Water Microbiology; D014875:Water Pollutants, Radioactive / Q000378:metabolism
chemical_list: D011850:Radioactive Waste; D014875:Water Pollutants, Radioactive; D014867:Water