Changes in prokaryotic community composition accom

Authors: Concetta Gugliandolo Valeria Lentini Boyke Bunk Jörg Overmann Francesco Italiano Teresa Luciana Maugeri

Publish Date: 2015/02/26

Volume: 19, Issue: 3, Pages: 547-559

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Abstract

Hot Lake is a recently described thermal brine pool off Panarea Island Eolian Islands Italy where emitted fluids are highly saline and rich in CO2 and H2S The prokaryotic community composition in surface sediment samples was analyzed by highthroughput Illumina sequencing targeting the V3 region of the 16S rRNA at two time points that differed mainly with respect to temperature conditions hightemperature 94 °C HT09 and lowtemperature 285 °C LT10 Bacterial richness and diversity were greater than those of Archaea under both temperature conditions In contrast to Bacteria diversity and evenness of Archaea greatly increased at LT10 While the phylogenetic analysis indicated the presence of members mostly affiliated with the same taxonomic groups their relative abundances differed from HT09 to LT10 resulting in different bacterial and archaeal assemblages Both HT09 and LT10 were dominated by members of the Epsilonproteobacteria Within this subphylum bacteria of the genus Sulfurimonas were most frequently detected at HT09 while Arcobacter prevailed at LT10 The abundance of other dominant taxonomic groups ≥1  of Illumina reads also correlated with temperature conditions Members assigned to hyperthermophilic Euryarchaeota Thermococci or to thermophilic Caldiserica and thermoresistant Firmicutes bacterial taxa were dominant at HT09 while those related to nonthermophilic Bacteroidetes Fusobacteria and Actinobacteria were dominant at LT10 Several probably photosynthetic members of the Alphaproteobacteria Chlorobi Cyanobacteria and Chloroflexi were recovered under both temperature conditions The cooccurrence of photosynthetic and chemolithotrophic microorganisms represents a unique feature of shallow vents such as Hot Lake

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