Diversity of Total Bacterial Communities and Chemoautotrophic Populations in Sulfur-Rich Sediments of Shallow-Water Hydrothermal Vents off Kueishan Island, Taiwan

The Zannone Giant Pockmark (ZGP) is a shallow-water (<−150 m) giant depression located on the shelf off Zannone Island (Pontine Archipelago, central Tyrrhenian Sea, Italy), hosting active hydrothermal vents. The ZGP seabed displays different fluid-venting morphologies (pockmarks, lithified pavements, mounds, and cone-shaped structures) and widespread bacterial communities. In this study, we analyzed ROV (Remote Operated Vehicle) images to gain information on seabed geology and the textural, mineralogical, and geochemical composition of authigenic crusts and gravel-sized clasts sampled close to active emissions. ROV images show authigenic dome-shaped crusts composed of native sulfur associated with barite, gypsum, amorphous silica, and secondary hydrothermal minerals (illite–montmorillonite). The gravel-sized clasts are mostly rhyolites strongly affected by hydrothermal alteration (Alteration Index > 88; depletion of some mobile elements and enrichment of some base metals), causing feldspar-destruction, silicification, formation of hydrothermal phyllosilicates, and precipitation of disseminated pyrite. More intense alteration implying the complete obliteration of the primary mineralogy or fabric is represented by quartz-pyrite samples. ZGP seabed morphology and petro-geochemical features of deposits point to the possible occurrence of a sulfide system linked to the degassing of magma similar to that feeding the Pleistocene products of Ponza Island.

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Culture-Independent Characterization of Bacterial Communities Associated with the Cold-Water Coral Lophelia pertusa in the Northeastern Gulf of Mexico

Applied and Environmental Microbiology ◽

10.1128/aem.02357-08 ◽

2009 ◽

Vol 75 (8) ◽

pp. 2294-2303 ◽

Cited By ~ 65

Author(s):

Christina A. Kellogg ◽

John T. Lisle ◽

Julia P. Galkiewicz

Keyword(s):

Gulf Of Mexico ◽

Shallow Water ◽

Bacterial Communities ◽

Cold Water ◽

Environmental Gradients ◽

Rrna Gene ◽

Lophelia Pertusa ◽

Culture Independent ◽

Northeastern Gulf Of Mexico ◽

Study Sites

ABSTRACT Bacteria are recognized as an important part of the total biology of shallow-water corals. Studies of shallow-water corals suggest that associated bacteria may benefit the corals by cycling carbon, fixing nitrogen, chelating iron, and producing antibiotics that protect the coral from other microbes. Cold-water or deep-sea corals have a fundamentally different ecology due to their adaptation to cold, dark, high-pressure environments and as such have novel microbiota. The goal of this study was to characterize the microbial associates of Lophelia pertusa in the northeastern Gulf of Mexico. This is the first study to collect the coral samples in individual insulated containers and to preserve coral samples at depth in an effort to minimize thermal shock and evaluate the effects of environmental gradients on the microbial diversity of samples. Molecular analysis of bacterial diversity showed a marked difference between the two study sites, Viosca Knoll 906/862 (VK906/862) and Viosca Knoll 826 (VK826). The bacterial communities from VK826 were dominated by a variety of unknown mycoplasmal members of the Tenericutes and Bacteroidetes, whereas the libraries from VK906/862 were dominated by members of the Proteobacteria. In addition to novel sequences, the 16S rRNA gene clone libraries revealed many bacterial sequences in common between Gulf of Mexico Lophelia corals and Norwegian fjord Lophelia corals, as well as shallow-water corals. Two Lophelia-specific bacterial groups were identified: a cluster of gammaproteobacteria related to sulfide-oxidizing gill symbionts of seep clams and a group of Mycoplasma spp. The presence of these groups in both Gulf and Norwegian Lophelia corals indicates that in spite of the geographic heterogeneity observed in Lophelia-associated bacterial communities, there are Lophelia-specific microbes.

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Antimicrobial Activity of Marine Bacterial Symbionts Retrieved from Shallow Water Hydrothermal Vents

Marine Biotechnology ◽

10.1007/s10126-016-9695-7 ◽

2016 ◽

Vol 18 (3) ◽

pp. 293-300 ◽

Cited By ~ 3

Author(s):

Arnheidur Eythorsdottir ◽

Sesselja Omarsdottir ◽

Hjorleifur Einarsson

Keyword(s):

Antimicrobial Activity ◽

Shallow Water ◽

Hydrothermal Vents ◽

Bacterial Symbionts

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Characterization of Bacterial Communities Associated with Deep-Sea Corals on Gulf of Alaska Seamounts

Applied and Environmental Microbiology ◽

10.1128/aem.72.2.1680-1683.2006 ◽

2006 ◽

Vol 72 (2) ◽

pp. 1680-1683 ◽

Cited By ~ 79

Author(s):

Kevin Penn ◽

Dongying Wu ◽

Jonathan A. Eisen ◽

Naomi Ward

Keyword(s):

Shallow Water ◽

Deep Sea ◽

Bacterial Communities ◽

Gulf Of Alaska ◽

Independent Analysis ◽

Deep Sea Corals

ABSTRACT Although microbes associated with shallow-water corals have been reported, deepwater coral microbes are poorly characterized. A cultivation-independent analysis of Alaskan seamount octocoral microflora showed that Proteobacteria (classes Alphaproteobacteria and Gammaproteobacteria), Firmicutes, Bacteroidetes, and Acidobacteria dominate and vary in abundance. More sampling is needed to understand the basis and significance of this variation.

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