Article

Heterotrophic denitrification at extremely high salt and pH by haloalkaliphilic Gammaproteobacteria from hypersaline soda lakes

Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-let Octyabrya 7/2, 117811 Moscow, Russia.
Extremophiles (Impact Factor: 2.17). 06/2008; 12(5):619-25. DOI: 10.1007/s00792-008-0166-6
Source: PubMed

ABSTRACT In this paper we describe denitrification at extremely high salt and pH in sediments from hypersaline alkaline soda lakes and soda soils. Experiments with sediment slurries demonstrated the presence of acetate-utilizing denitrifying populations active at in situ conditions. Anaerobic enrichment cultures at pH 10 and 4 M total Na+ with acetate as electron donor and nitrate, nitrite and N2O as electron acceptors resulted in the dominance of Gammaproteobacteria belonging to the genus Halomonas. Both mixed and pure culture studies identified nitrite and N2O reduction as rate-limiting steps in the denitrification process at extremely haloalkaline conditions.

Electronic supplementary material
The online version of this article (doi:10.1007/s00792-008-0166-6) contains supplementary material, which is available to authorized users.

0 Followers
 · 
86 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study investigates the reactivity of nitrates in abiotic and biotic conditions at alkaline pH in the context of a repository for long-lived inter-mediate-level radioactive waste. The work, carried out under environmental conditions comparable to those prevailing in the repository: alkaline pH, no oxygen, solid materials (cementitious material, steel), aims to identify the by-products of the nitrate reduction and to evaluate reaction kinetics of these reactions with and without the presence of denitrifying microorganisms. This paper demonstrates that, even at the high pH characteristic of nuclear waste repositories, nitrate reduction may be a likely scenario, with biotic catalysis in the presence of microorganisms and surface catalysis in the presence of steel and/or corrosion products.
    International Biodeterioration & Biodegradation 07/2015; 101:12-22. DOI:10.1016/j.ibiod.2015.03.013 · 2.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have studied the diversity and distribution of Halomonas populations in the hypersaline habitat Rambla Salada (Murcia, south-eastern Spain) by using different molecular techniques. Denaturing gradient gel electrophoresis (DGGE) using specific primers for the 16S rRNA gene of Halomonas followed by a multivariate analysis of the results indicated that richness and evenness of the Halomonas populations were mainly influenced by the season. We found no significant differences between the types of samples studied, from either watery sediments or soil samples. The highest value of diversity was reached in June 2006, the season with the highest salinity. Furthermore, canonical correspondence analysis (CCA) demonstrated that both salinity and pH significantly affected the structure of the Halomonas community. H. almeriensis and two denitrifiers, H. ilicicola and H. ventosae, were the predominant species. CARD-FISH showed that the percentage of Halomonas cells with respect to the total number of microorganisms ranged from 4.4% to 5.7%. To study the functional role of denitrifying species, we designed new primer sets targeting denitrification nirS and nosZ genes. Using these primers we analysed sediments from the upwelling zone collected in June 2006, where we found the highest percentage of denitrifiers (74%). H. ventosae was the predominant denitrifier in this site. This article is protected by copyright. All rights reserved.
    FEMS Microbiology Ecology 10/2013; 87(2). DOI:10.1111/1574-6941.12237 · 3.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To explore the influence of cyanobacteria blooms on internal nutrient loading and sediment biogeochemistry, we conducted a 3 yr (2008–2010) field investigation in the upper Sassafras River, a shallow tidal freshwater tributary of Chesapeake Bay, Maryland. During 2010 a dense diazotrophic cyanobacteria bloom was accompanied by abnormally high pH (9.0–10.5) and supersaturated oxygen throughout the summer. With the persistence of high pH in the water column and organic matter inputs from sedimented phytoplankton detritus, flux rates of NH z
    Limnology and Oceanography 05/2014; 59(3). DOI:10.4319/lo.2014.59.3.0959 · 3.62 Impact Factor

Full-text (2 Sources)

Download
27 Downloads
Available from
Jun 10, 2014