Thioploca araucae
A Microbial Biorealm page on the genus Thioploca araucae
Classification
Cellular Organisms; Bacteria; Proteobacteria; Gammaproteobacteria; Thiotrichales; Thiotrichaceae; Thioploca; Thioploca araucae
Species
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NCBI: Taxonomy |
Thioploca araucae
Description and significance
Marine species of Thioploca occur over 3,000 km along the continental shelf off Southern Peru and North and Central Chile. These filamentous bacteria live in bundles surrounded by a common sheath and form thick mats on the sea floor under the oxygen-minimum zone in the upwelling region, at between 40 and 280 m water depth. It serves as a bridge between the nitrogen and sulfur cycles. After taking in nitrage, gliding filaments transport this nitrate 5–10 cm down into the sediment and reduce it, with concomitant oxidation of hydrogen sulphide, thereby coupling the nitrogen and sulphur cycles in the sediment (1). Thioploca araucae is a filamentous sulfur-oxidizing bacterium. It is typically found in bacterial mats in sediment layers at the bottom of the ocean. Thioploca has been found off the coast of Chile and Namibia, as well as in freshwater areas in Japan.
Genome structure
The genome is currently being sequenced as part of the Moore Foundation Microbial Genome Sequencing project. A sample collected by Victor Gallardo on the continental shelf off of Concepcion, Chile is being studied by the J Craig Venter Institute.
Cell structure and metabolism
The metabolism of this marine bacterium remained a mystery until long after its discovery. We report here that Thioploca cells are able to concentrate nitrate to up to 500 mM in a liquid vacuole that occupies >80% of the cell volume (1). Gliding filaments transport this nitrate 5–10 cm down into the sediment and reduce it, with concomitant oxidation of hydrogen sulphide, thereby coupling the nitrogen and sulphur cycles in the sediment
nitrate principal electron acceptor
link the sulfur and nitrogen cycles
Ecology
Thioploca cells form filaments that cling to each other and secrete an encompassing sheath of mucous film. The sheath serves as a kind of vertical tunnel through the sediment up to the overlying water, allowing the Thioploca filaments to glide up and down and thereby commute between their food source and the nitrate they need to metabolize it. It is estimated that close to one-quarter of global marine denitrification is done in the upwelling waters off the Pacific coast of South America (2). Thioploca araucae, along with other sulfur oxidizers such as Beggiatoa, plays a major role in this.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Enter summaries of the most recent research here--at least three required
References
1. H. Fossing, V.A. Gallardo, et. al. Concentration and transport of nitrate by the mat-forming sulphur bacterium Thioploca. Nature 374, 713-715 (1995).
2. Codispoti, L.A. et al. Science 233, 1200-1202 (1986).
Edited by student of Rachel Larsen
Bo Barker Jørgensen, Victor A Gallardo (1999) Thioploca spp.: filamentous sulfur bacteria with nitrate vacuoles FEMS Microbiology Ecology 28 (4), 301–313.
Nitrogen, Carbon, and Sulfur Metabolism in Natural Thioploca Samples
Vertical Migration in the Sediment-Dwelling Sulfur Bacteria Thioploca spp. in Overcoming Diffusion Limitations MARKUS HUETTEL,* STEFAN FORSTER, SUSANNE KLO¨ SER, AND HENRIK FOSSING Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany
Population study of the filamentous sulfur bacteria Thioploca spp. off the Bay of Concepcion, Chile Heide N. Schulzl~*B, ettina Strotmannl, Victor A. Gallardo2, Bo B. ~ergensen' 'Max Planck Institute for Marine Microbiology, Celsiusstrasse 1.28359 Bremen, Germany
Maier S & Gallardo VA (1984) Maier, S., and Gallardo, V.A. "Thioploca araucae sp. nov. and Thioploca chileae sp. nov." Int. J. Syst. Bacteriol. (1984) 34:414-418. [No PubMed record available.]
