Thioploca araucae

From MicrobeWiki, the student-edited microbiology resource

A Microbial Biorealm page on the genus Thioploca araucae

Classification

Cellular Organisms; Bacteria; Proteobacteria; Gammaproteobacteria; Thiotrichales; Thiotrichaceae; Thioploca; Thioploca araucae

Species

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 by the J Craig Venter Institute.

Cell structure and metabolism

The metabolism of this marine bacterium5,6 remained a mystery until long after its discovery1,7. 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. 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.

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. Concentration and transport of nitrate by the mat-forming sulphur bacterium Thioploca H. Fossing*, V. A. Gallardo†,


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.]