Biodiversity of prokaryotic communities in sediments of different sub-basins of the Venice lagoon

Abstract

Microbial community structure and diversity in the wide and shallow Venice lagoon were assessed, prior to construction of mobile dams, at nine stations representative of four different sub-basins previously selected on the basis of international guidelines for sediment quality. The sediments were mainly anoxic and were colonized by microbial communities the species richness of which was quantitatively correlated with total elemental sulfur and acid-volatile sulfide. Automated ribosomal intergenic spacer analysis clustered the stations into three groups. One station for each group was hence analyzed in detail for bacterial and archaeal diversity by screening of 16S rRNA gene clone libraries. The dominance of Gammaproteobacteria clones (84% with a high proportion of Vibrionaceae, indicator of urban pollution) determined significant divergence of the station adjacent to industrial and metropolitan areas. Bacteroidetes were widespread, especially where prairies of aquatic plants are located. The other two analyzed stations were dominated by bacterial taxa implicated in the sulfur cycle: the anoxygenic photosynthetic Chromatiales, sulfate-and sulfur-reducing Desulfobacterales and Desulfuromonadales, and members of the Alpha-and Epsilonproteobacteria.

Three manganese oxide-rich marine sediments harbor similar communities of acetate-oxidizing manganese-reducing bacteria

“…Sequences of Oceanospirillaceae and Colwellia are frequently recovered in molecular studies of marine waters and sea ice (DeLong et al, 1993;Gosink and Staley, 1995;Bowman et al, 1997;Brown and Bowman, 2001;Koskinen et al, 2011). One additional report is from a sediment (Borin et al, 2009), but judging from the eutrophic coastal setting, manganese reduction is not likely to be important there either. Isolates of these two gammaproteobacterial taxa are mainly of marine origin (Deming et al, 1988;Gosink and Staley, 1995;Bowman et al, 1998;Yumoto et al, 1998;Hedlund et al, 1999;Nogi et al, 2004;Jung et al, 2006).…”

Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile

“…16S rRNA sequences and fosmids of the uncultured candidate division MSBL1 have been retrieved from hypersaline anoxic environments such as the deep-sea hypersaline anoxic brines in the Mediterranean Sea (van der Wielen et al, 2005; Daffonchio et al, 2006; Borin et al, 2009; Yakimov et al, 2013) and a hypersaline microbial mat of a solar saltern (López-López et al, 2013). The majority of archaeal 16S rRNA sequences recovered from these ecosystems belonged to the uncultured candidate division MSBL1 and combined methane production that was observed suggests that this archaeal lineage is involved in methanogenesis at extreme salinities.…”

Cultivation-independent methods applied to the microbial prospection of oil and gas in soil from a sedimentary basin in Brazil

“…The order Desulfuromonadales (Deltaproteobacteria), constituted mainly by anaerobic bacteria [Thomas et al 2008], was also detected. This group encompasses mainly sulfate-reducing bacteria [Borin et al 2009] and several species possessing this metabolism may present in addition the ability of degrading short-chain hydrocarbons [Kniemeyer et al 2007]. …”