The Thermoproteota are archaea that have been classified as a phylum of the Archaea domain. Initially, the Thermoproteota were thought to be sulfur-dependent extremophiles but recent studies have identified characteristic Thermoproteota environmental rRNA indicating the organisms may be the most abundant archaea in the marine environment. Originally, they were separated from the other archaea based on rRNA sequences; other physiological features, such as lack of histones, have supported this division, although some crenarchaea were found to have histones. Until recently all cultured Thermoproteota had been thermophilic or hyperthermophilic organisms, some of which have the ability to grow at up to 113 °C. These organisms stain Gram negative and are morphologically diverse, having rod, cocci, filamentous and oddly-shaped cells.
Thermithiobacillus is a genus of nonsporeforming, rod-shaped, Gram-negative bacteria. The name derives from the Latin thermae, for warm baths, and the Classical Greek θείος, theios for sulfur. The type species of this genus was previously assigned to the genus Thiobacillus, but it was reclassified on the basis of 16S rRNA analysis in 2000, creating this genus.
The Thermodesulfobacteriota are a phylum of thermophilic sulfate-reducing bacteria.
Sulfur-reducing bacteria are microorganisms able to reduce elemental sulfur (S0) to hydrogen sulfide (H2S). These microbes use inorganic sulfur compounds as electron acceptors to sustain several activities such as respiration, conserving energy and growth, in absence of oxygen. The final product or these processes, sulfide, has a considerable influence on the chemistry of the environment and, in addition, is used as electron donor for a large variety of microbial metabolisms. Several types of bacteria and many non-methanogenic archaea can reduce sulfur. Microbial sulfur reduction was already shown in early studies, which highlighted the first proof of S0 reduction in a vibrioid bacterium from mud, with sulfur as electron acceptor and H
2 as electron donor. The first pure cultured species of sulfur-reducing bacteria, Desulfuromonas acetoxidans, was discovered in 1976 and described by Pfennig Norbert and Biebel Hanno as an anaerobic sulfur-reducing and acetate-oxidizing bacterium, not able to reduce sulfate. Only few taxa are true sulfur-reducing bacteria, using sulfur reduction as the only or main catabolic reaction. Normally, they couple this reaction with the oxidation of acetate, succinate or other organic compounds. In general, sulfate-reducing bacteria are able to use both sulfate and elemental sulfur as electron acceptors. Thanks to its abundancy and thermodynamic stability, sulfate is the most studied electron acceptor for anaerobic respiration that involves sulfur compounds. Elemental sulfur, however, is very abundant and important, especially in deep-sea hydrothermal vents, hot springs and other extreme environments, making its isolation more difficult. Some bacteria – such as Proteus, Campylobacter, Pseudomonas and Salmonella – have the ability to reduce sulfur, but can also use oxygen and other terminal electron acceptors.
Pseudomonas balearica is a Gram-negative, rod-shaped, nonfluorescent, motile, and denitrifying bacterium. It is an environmental bacterium that has been mostly isolated from polluted environments all over the world. Many of the isolates have demonstrated capabilities to degrade several compounds. Some of the strains are naphthalene degraders and one strain isolated in New Zealand has demonstrated the potential to oxidize inorganic sulfur compounds to tetrathionate. Based on 16S rRNA analysis, P. balearica has been placed in the P. stutzeri group.
In taxonomy, Aeropyrum is a genus of the Desulfurococcaceae.
In taxonomy, Staphylothermus is a genus of the Desulfurococcaceae.[1]
Thermithiobacillus tepidarius is a member of the Acidithiobacillia isolated from the thermal groundwaters of the Roman Baths at Bath, Somerset, United Kingdom. It was previously placed in the genus Thiobacillus. The organism is a moderate thermophile, 43–45 °C (109–113 °F), and an obligate aerobic chemolithotrophic autotroph. Despite having an optimum pH of 6.0–7.5, growth can continue to an acid medium of pH 4.8. Growth can only occur on reduced inorganic sulfur compounds and elementary sulfur, but unlike some species in other genus of the same family, Acidithiobacillus, Thermithiobacillus spp. are unable to oxidise ferrous iron or iron-containing minerals.
Oxobacter is a genus of Gram-positive obligately anaerobic rod-shaped acetogenic bacteria. The sole species in the genus is Oxobacter pfennigii, formerly known as Clostridium pfennigii. This endospore-forming microorganism catabolizes pyruvate to acetate and CO2, while sugars and amino acids are not utilized as energy sources.
Thermoanaerobacter is a genus in the phylum Bacillota (Bacteria). Members of this genus are thermophilic and anaerobic, several of them were previously described as Clostridium species and members of the now obsolete genera Acetogenium and Thermobacteroides
Caldicellulosiruptor saccharolyticus is a species of thermophilic, anaerobic cellulolytic bacterium. It was isolated from a piece of wood floating in the flow from a freshwater thermal spring in New Zealand in 1987, and tentatively named Caldocellum saccharolyticum. In 1994, the isolate was more thoroughly characterized physiologically, and classified to a new genus, Caldicellusiruptor, based on 16S RNA sequence. It is the type species, and more thoroughly studied member of its genus.
Hydrogenovibrio crunogenus is a colorless, sulfur-oxidizing bacterium first isolated from a deep-sea hydrothermal vent. It is an obligate chemolithoautotrophic sulfur oxidizer and differs from other species of this genus by its DNA base composition and by its growth rate and optimal pH in thiosulfate medium. ATCC 35932T is the type strain of the species. It was originally published in the genus Thiomicrospira as Thiomicrospira crunogena but was reclassified to the genus Hydrogenovibrio in 2017, resulting a grammatical gender change of the specific epithet from crunogena to crunogenus. The genome sequence of H. crunogenus XCL-2 has been published but that of the type strain has not yet been undertaken.
Desulfurella kamchatkensis is a thermophilic sulfur-reducing eubacterium. It is Gram-negative, rod-shaped, motile, with a single polar flagellum and type strain K-119T.
Thiomicrospira aerophila is an obligately alkaliphilic and obligately chemolithoautotrophic sulfur-oxidizing bacterium that was previously the type species of Thioalkalimicrobium prior to reclassification in 2017. It was first isolated from soda lakes in northern Russia.
Thiomicrospira siberica is a species of obligately alkaliphilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria. It was first isolated from soda lakes in northern Russia, hence the specific epithet. In 2017, all 4 species of the genus Thioalkalimicrobium were reclassified to Thiomicrospira.
Thioalkalivibrio versutus is an obligately alkaliphilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria. It was first isolated from soda lakes in northern Russia.
Thioalkalivibrio nitratis is an obligately alkaliphilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria. It was first isolated from soda lakes in northern Russia.
Thioalkalivibrio denitrificancs is an obligately alkaliphilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria. It was first isolated from soda lakes in northern Russia.
Thioalkalivibrio thiocyanoxidans is a species of alkaliphilic and obligately autotrophic sulfur-oxidizing bacterium. It was first isolated from soda lakes. Its type strain is Arh 2.
The Ignavibacteriales are an order of obligately anaerobic, non-photosynthetic bacteria that are closely related to the green sulfur bacteria.
