Ferroplasma acidiphilum: Difference between revisions
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==Description and Significance== | ==Description and Significance== | ||
Ferroplasma acidiphilum is a species of | Ferroplasma acidiphilum is a species of an iron-oxidizing, acidophilic, chemolithoautotrophic archaea. It lives in a metal-heavy environment containing high levels of iron and sulfur at a very acidic pH. It has been categorized as an extremophile as it grows optimally at a pH of 1.7. It was first isolated from a bioreactor pilot plant in Tula, Russia. The bioreactor was used to leach gold from pyrite-ore, a chemical reaction that F. acidiphilum plays a role in. It is part of the order Thermoplasmata that contains other acidophilic genera including Picrophilus and Thermoplasma. F. acidiphilum and its sister species F. acidarmanus play a large role in geochemical cycling of iron and sulfur in very acidic, metal-heavy habitats both natural and man-made. It has been found that some of its intracellular enzymes function optimally at pH levels as low as 1.7, much lower than what the actual cytoplasmic pH level of 5.6. This has led to research aimed at determining how this "pH anomaly" exists and how this organism has evolved to survive this way. | ||
Describe the organism habitat, etc. of the organism, and why you think it is important. | Describe the organism habitat, etc. of the organism, and why you think it is important. | ||
Revision as of 20:28, 21 April 2010
Classification
Domain (Archaea); Phylum (Euryarchaeota); Class (Thermoplasmata); Order (Thermoplasmatales); Family (Ferroplasmaceae); Genus (Ferroplasma)
Species
Ferroplasma acidiphilum
Description and Significance
Ferroplasma acidiphilum is a species of an iron-oxidizing, acidophilic, chemolithoautotrophic archaea. It lives in a metal-heavy environment containing high levels of iron and sulfur at a very acidic pH. It has been categorized as an extremophile as it grows optimally at a pH of 1.7. It was first isolated from a bioreactor pilot plant in Tula, Russia. The bioreactor was used to leach gold from pyrite-ore, a chemical reaction that F. acidiphilum plays a role in. It is part of the order Thermoplasmata that contains other acidophilic genera including Picrophilus and Thermoplasma. F. acidiphilum and its sister species F. acidarmanus play a large role in geochemical cycling of iron and sulfur in very acidic, metal-heavy habitats both natural and man-made. It has been found that some of its intracellular enzymes function optimally at pH levels as low as 1.7, much lower than what the actual cytoplasmic pH level of 5.6. This has led to research aimed at determining how this "pH anomaly" exists and how this organism has evolved to survive this way.
Describe the organism habitat, etc. of the organism, and why you think it is important.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Life Cycle, Cell Structure, and Metabolism
Interesting features of cell structure; how it gains energy; what important molecules it produces.
F. acidiphilum cells can come in a variety of forms depending on environmental conditions and growth stage. At the beginning of the exponential growth phase cells have irregular round shapes. As growth continues cells can take on other unusual shapes, including a vibrio-like form. Cells in the stationary phase are pleomorphic and assume irregular shapes (pivovarova). Cells also take on irregular shapes when budding. Because of the large number of forms a f. acidiphilum cell can take, cell sizes vary greatly but typically have a diameter of 0.3-3μm (golyshina 2005).
All cells in the Ferroplasma genus lack cell walls. Under acidic conditions the ether-linked membrane lipids of archaea are more resistant to acid hydrolysis than the ester-linked membrane lipids of Bacteria and Eukaryotes. F. acidiphilum membranes are mainly composed of unique tetraether lipids that form a monolayer giving the membrane more stability. One of the main constituents of the membrane, β-D-glucopyranosylcaldarchaetidylglycerol, comprises 55% of the membrane and contains cyclopentane rings, giving the membrane more rigidity (batrakov 2002). The membrane composition of F. acidiphilum and other acidophilic archaea cells create large proton gradients due to their low proton permeability, allowing the cells to survive at very acidic pH levels. Membrane proteins of this species function optimally up to 3 pH levels below the mean cytoplasmic pH of 5 (macalady).
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
References
Author
Page authored by Nathan I. Johns and Indumathy Jayamani, students of Prof. Jay Lennon at Michigan State University.
