Comparative analysis of bacterioplankton assemblages from maritime Antarctic freshwater lakes with contrasting trophic status

SCHIAFFINO, M. R.; UNREIN, F.; GASOL, J. M.; FARIAS, M. E.; ESTEVEZ, C.; BALAGUÉ, V.; IZAGUIRRE, I.

POLAR BIOLOGY

Springer

Año: 2009 vol. 32 p. 923 - 936

0722-4060

The bacterioplankton assemblages of eightmaritime Antarctic lakes with a wide range of trophic statusand geographic span (six lakes from Hope Bay, AntarcticPeninsula and two from Potter Peninsula, King GeorgeIsland) were described using denaturing gradient gelelectrophoresis and band sequencing during two consecutiveaustral summers (2003–2004). Analyses of the gelsidentified a total of 230 bands spread across 57 diferentpositions. Among those bands, 14 were shared betweenlakes from Hope Bay and Potter Peninsula, 17 wereobserved only in particular lakes, and 17 were registeredboth years in the same lake. We successfully reamplified and sequenced 43 bands located in 36 diVerent positionsbelonging to Bacteroidetes, Actinobacteria, Betaproteobacteriaand Cyanobacteria. The closest matches for 63% ofthe sequenced bands were from Antarctic or from othercold environment clones and sequences already in the databases,suggesting the widespread dominance of microbialcommunities adapted to cold habitats. The results of themultivariate analyses (Cluster Analysis and CCA) indicatedthat the nutrient status of the lake influences the bacterioplanktonassemblages.