Search results for "hydrothermal vent"
showing 10 items of 29 documents
2-D difference gel electrophoresis approach to assess protein expression profiles in Bathymodiolus azoricus from Mid-Atlantic Ridge hydrothermal vent…
2011
Hydrothermal vent mussels Bathymodiolus azoricus are naturally exposed to toxic chemical species originated directly from vent chimneys. The amount of toxic elements varies significantly among vent sites along the Mid-Atlantic Ridge and B. azoricus must be able to adapt to changes in hydrothermal fluid composition, temperature and pressure. The aim of this work was to study changes in the proteome in the "gill-bacteria complex" of mussels B. azoricus from three hydrothermal vent sites with distinct environmental characteristics using 2-D Fluorescence Difference Gel Electrophoresis (2-D DIGE). Results showed that 31 proteins had different expression profiles among vent sites and both cluster…
Geosphere-biosphere interactions in bio-activity volcanic lakes: Evidences from Hule and Rìo Cuarto (Costa Rica)
2014
Hule and R ́ıo Cuarto are maar lakes located 11 and 18 km N of Poa ́s volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemica…
Petrography and high-resolution geochemical records of Lower Jurassic manganese-rich deposits from Monte Mangart, Julian Alps
2016
Deposits with unusually high Mn contents sampled at Monte Mangart in the Julian Alps include organic-rich marlstone and black shale with interbedded manganoan and siliceous limestone, which were deposited during the early Toarcian Oceanic Anoxic Event. Mn enrichment during that period has been related to global sea-level change coincident with increasing subsidence rate. The formation of Fe-Mn nodules, marking a hardground at the base of the Monte Mangart section, seems to be triggered by release of Mn from remote hydrothermal vents into a region of relatively elevated submarine topography where oxidizing conditions prevailed. However, very high Mn contents in carbonate phases above the har…
Comparison of thiol subproteome of the vent mussel Bathymodiolus azoricus from different Mid-Atlantic Ridge vent sites
2012
Deep-sea hydrothermal mussels Bathymodiolus azoricus live in the mixing zone where hydrothermal fluid mixes with bottom seawater, creating large gradients in the environmental conditions and are one of the most studied hydrothermal species as a model of adaptation to extreme conditions. Thiol proteins, i.e. proteins containing a thiol or sulfhydryl group (SH) play major roles in intracellular stress defense against reactive oxygen species (ROS) and are especially susceptible to oxidation. However, they are not particularly abundant, representing a small percentage of proteins in the total proteome and therefore are difficult to study by proteomic approaches. Activated thiol sepharose (ATS) …
Thermal restraint of a bacterial exopolysaccharide of shallow vent origin
2018
This is the post-print version of the following article: "Thermal restraint of a bacterial exopolysaccharide of shallow vent origin", which has been published in final form at https://www.sciencedirect.com/science/article/pii/S0141813018308250?via%3Dihub; International audience; To dynamically characterize the thermal properties of the fructose-rich exopolysaccharide (EPS1-T14), produced by themarine thermophilic Bacillus licheniformis T14, the Attenuated Total Reflectance Fourier Transform Infra-Redspectroscopy was coupled to variable temperature ranging from ambient to 80 °C.The spectra were analyzed by the following innovative mathematical tools: i) non-ideal spectral deviation, ii) OHst…
Marine biominerals: perspectives and challenges for polymetallic nodules and crusts.
2009
Deep sea minerals in polymetallic nodules, crusts and hydrothermal vents are not only formed by mineralization but also by biologically driven processes involving microorganisms (biomineralization). Within the nodules, free-living and biofilm-forming bacteria provide the matrix for manganese deposition, and in cobalt-rich crusts, coccolithophores represent the dominant organisms that act as bio-seeds for an initial manganese deposition. These (bio)minerals are economically important: manganese is an important alloying component and cobalt forms part of special steels in addition to being used, along with other rare metals, in plasma screens, hard-disk magnets and hybrid car motors. Recent p…