Prokaryotic Community in Lacustrine Sediments of Byers Peninsula (Livingston Island, Maritime Antarctica)

• Published in: Microbial Ecology
• Main Authors: GUGLIANDOLO, Concetta, MICHAUD, LUIGI, LO GIUDICE, ANGELINA, LENTINI, VALERIA, Rochera, Carlos, Camacho, Antonio, MAUGERI, Teresa Luciana
• Other Authors: Gugliandolo, Concetta, Michaud, Luigi, Lo Giudice, Angelina, Lentini, Valeria, Rochera, Carlo, Maugeri, Teresa Luciana
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: Bacterial diversity; Maritime Antarctic lakes; 454 Pyrosequencing; Antarc*; Antarctic; Antarctica; Livingston Island
• Online Access: http://hdl.handle.net/11570/3079767; https://doi.org/10.1007/s00248-015-0666-8

Byers Peninsula (Livingston Island, Antarctica), the largest seasonally ice-free region of the Maritime Antarctica, holds a large number of lakes, ponds, and streams. The prokaryotic structure and bacterial diversity in sediment samples collected during the 2008–2009 austral summer from five inland lakes, two coastal lakes, and an estuarine site were analyzed by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) and 16S rRNA 454 tag pyrosequencing techniques, respectively. Differently from inland lakes, which range around the oligotrophic status, coastal lakes are eutrophic environments, enriched by nutrient inputs from marine animals. Although the prokaryotic abundances (estimated as DAPI stained cells) in sediment samples were quite similar among inland and coastal lakes, Bacteria always far dominated over Archaea. Despite the phylogenetic analysis indicated that most of sequences were affiliated to a few taxonomic groups, mainly referred to Proteobacteria, Bacteroidetes, and Actinobacteria, their relative abundances greatly differed from each site. Differences in bacterial composition showed that lacustrine sediments were more phyla rich than the estuarine sediment. Proteobacterial classes in lacustrine samples were dominated by Betaproteobacteria (followed by Alphaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria), while in the estuarine sample, they were mainly related to Gammaproteobacteria (followed by Deltaproteobacteria, Epsilonproteobacteria, Alphaproteobacteria, and Betaproteobacteria).Higher number of sequences of Alphaproteobacteria, Cyanobacteria, Verrucomicrobia, and Planctomycetes were observed in sediments of inland lakes compared to those of coastal lakes, whereas Chloroflexi were relatively more abundant in the sediments of coastal eutrophic lakes. As demonstrated by the great number of dominant bacterial genera, bacterial diversity was higher in the sediments of inland lakes than that in coastal lakes. Ilumatobacter (Actinobacteria), Gp16 (Acidobacteria), ...