A close link between bacterial community composition and environmental heterogeneity in maritime Antarctic lakes

Autors/ores

  • Juan A. Villaescusa Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain
  • Emilio O. Casamayor Department of Continental Ecology, CEAB-CSIC, Blanes, Spain
  • Carlos Rochera Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain
  • David Velázquez Department of Biology, Autonomous University of Madrid, Spain
  • Álvaro Chicote ETSICCP, University of Castilla-La Mancha, Spain
  • Antonio Quesada Department of Biology, Autonomous University of Madrid, Spain
  • Antonio Camacho Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

Paraules clau:

maritime Antarctic lakes, bacterioplankton, aquatic trophic status

Resum

Seven maritime Antarctic lakes located on Byers Peninsula (Livingston Island, South Shetland Islands) were surveyed to determine the relationship between planktonic bacterial community composition and environmental features. Specifically, the extent to which factors other than low temperature determine the composition of bacterioplankton assemblages of maritime Antarctic lakes was evaluated. Both deep and shallow lakes in the central plateau of the Peninsula, as well as a coastal lake, were studied in order to fully account for the environmental heterogeneity of the Peninsula’s lakes. The results showed that shallow coastal lakes display eutrophic conditions, mainly due to the influence of marine animals, whereas plateau lakes are generally deeper and most are oligotrophic, with very limited inputs of nutrients and organic matter. Meso-eutrophic shallow lakes are also present on the Peninsula; they contain microbial mats and a higher trophic status because of the biologically mediated active nutrient release from the sediments. Diversity studies of the lakes’ planktonic bacterial communities using molecular techniques showed that bacterial diversity is lower in eutrophic than in oligotrophic lakes. The former also differed in community composition with respect to dominant taxa. Multivariate statistical analyses of environmental data yielded the same clustering of lakes as obtained based on the DGGE band pattern after DNA extraction and amplification of 16S rRNA gene fragments. Thus, even in extremely cold lakes, the bacterial community composition parallels other environmental factors, such as those related to trophic status. This correspondence is not only mediated by the influence of marine fauna but also by processes including sediment and ice melting dynamics. The bacterial community can therefore be considered to be equally representative as environmental abiotic variables in demonstrating the environmental heterogeneity among maritime Antarctic lakes. [Int Microbiol 2010; 13(2):67-77]

Biografies de l'autor/a

Juan A. Villaescusa, Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

Emilio O. Casamayor, Department of Continental Ecology, CEAB-CSIC, Blanes, Spain

Department of Continental
Ecology, CEAB-CSIC, Blanes, Spain

Carlos Rochera, Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

David Velázquez, Department of Biology, Autonomous University of Madrid, Spain

Department of Biology, Autonomous University of Madrid, Spain

Álvaro Chicote, ETSICCP, University of Castilla-La Mancha, Spain

ETSICCP, University of Castilla-La Mancha, Spain

Antonio Quesada, Department of Biology, Autonomous University of Madrid, Spain

Department of Biology, Autonomous University of Madrid, Spain

Antonio Camacho, Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Spain

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Publicat

2010-09-20

Número

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Articles