Desulfotomaculum | |
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Scientific classification | |
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Genus: | Desulfotomaculum Campbell & Postgate 1965 |
Type species | |
Desulfotomaculum nigrificans [1] | |
Species | |
D. acetoxidans [1] |
Desulfotomaculum is a genus of Gram-positive, obligately anaerobic soil bacteria. A type of sulfate-reducing bacteria, Desulfotomaculum can cause food spoilage in poorly processed canned foods.[ citation needed ] Their presence can be identified by the release of hydrogen sulfide gas with its rotten egg smell when the can is first opened. They are endospore-forming bacteria.[ citation needed ]
In 2005, a new strain of Desulfotomaculum, called Desulforudis audaxviator , was discovered during drilling 2.8 km deep in the Mponeng gold mine in South Africa. The strain, found in water which has been isolated for tens of millions of years, exists completely independent of photosynthesis. [2] The bacteria uses radiolytically produced hydrogen gas, which is generated in that environment by the energy released by radioisotopes. The bacteria also uses sulfates. Sulfates may be generated both by the energy released by radioisotopes as well as by other chemical reactions. Generated hydrogen sulfide may be a continuous energy source for this organism. [3] Some organisms can obtain energy from sources other than from the sun or other stars, which means similar lifeforms may be found on other planets in the Solar System and elsewhere.
Desulfotomaculum present as straight or curved rods. They are highly heat resistant and free-living fixers of atmospheric nitrogen. They are motile with a peritrichous flagella and are common inhabitants of soil, water, geothermal run-off, insect intestines and in rumen. They also cause "sulphide stinker" spoilage of canned foods.
Sulfur (also spelled sulphur in British English) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature.
Thiomargarita namibiensis is a gram-negative, facultative anaerobic, coccoid bacterium found in South America's ocean sediments of the continental shelf of Namibia. The genus name Thiomargarita means "sulfur pearl." This refers to the cells' appearance as they contain microscopic elemental sulfur granules just below the cell wall that refract light creating a pearly iridescent luster. The cells are each covered in a mucus sheath aligned in a chain, resembling loose strings of pearls. The species name namibiensis means "of Namibia".
Hydrogen sulfide is a chemical compound with the formula H2S. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777.
The green sulfur bacteria are a phylum, Chlorobiota, of obligately anaerobic photoautotrophic bacteria that metabolize sulfur.
In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules and nutrients into organic matter using the oxidation of inorganic compounds or ferrous ions as a source of energy, rather than sunlight, as in photosynthesis. Chemoautotrophs, organisms that obtain carbon from carbon dioxide through chemosynthesis, are phylogenetically diverse. Groups that include conspicuous or biogeochemically important taxa include the sulfur-oxidizing Gammaproteobacteria, the Campylobacterota, the Aquificota, the methanogenic archaea, and the neutrophilic iron-oxidizing bacteria.
The purple sulfur bacteria (PSB) are part of a group of Pseudomonadota capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in stratified water environments including hot springs, stagnant water bodies, as well as microbial mats in intertidal zones. Unlike plants, algae, and cyanobacteria, purple sulfur bacteria do not use water as their reducing agent, and therefore do not produce oxygen. Instead, they can use sulfur in the form of sulfide, or thiosulfate (as well, some species can use H2, Fe2+, or NO2−) as the electron donor in their photosynthetic pathways. The sulfur is oxidized to produce granules of elemental sulfur. This, in turn, may be oxidized to form sulfuric acid.
Acidithiobacillus is a genus of the Acidithiobacillia in the phylum "Pseudomonadota". This genus includes ten species of acidophilic microorganisms capable of sulfur and/or iron oxidation: Acidithiobacillus albertensis, Acidithiobacillus caldus, Acidithiobacillus cuprithermicus, Acidithiobacillus ferrianus, Acidithiobacillus ferridurans, Acidithiobacillus ferriphilus, Acidithiobacillus ferrivorans, Acidithiobacillus ferrooxidans, Acidithiobacillus sulfuriphilus, and Acidithiobacillus thiooxidans.A. ferooxidans is the most widely studied of the genus, but A. caldus and A. thiooxidans are also significant in research. Like all "Pseudomonadota", Acidithiobacillus spp. are Gram-negative and non-spore forming. They also play a significant role in the generation of acid mine drainage; a major global environmental challenge within the mining industry. Some species of Acidithiobacillus are utilized in bioleaching and biomining. A portion of the genes that support the survival of these bacteria in acidic environments are presumed to have been obtained by horizontal gene transfer.
Sulfate-reducing microorganisms (SRM) or sulfate-reducing prokaryotes (SRP) are a group composed of sulfate-reducing bacteria (SRB) and sulfate-reducing archaea (SRA), both of which can perform anaerobic respiration utilizing sulfate (SO2−
4) as terminal electron acceptor, reducing it to hydrogen sulfide (H2S). Therefore, these sulfidogenic microorganisms "breathe" sulfate rather than molecular oxygen (O2), which is the terminal electron acceptor reduced to water (H2O) in aerobic respiration.
The important sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element (CHNOPS), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. The global sulfur cycle involves the transformations of sulfur species through different oxidation states, which play an important role in both geological and biological processes. Steps of the sulfur cycle are:
Lithotrophs are a diverse group of organisms using an inorganic substrate to obtain reducing equivalents for use in biosynthesis or energy conservation via aerobic or anaerobic respiration. While lithotrophs in the broader sense include photolithotrophs like plants, chemolithotrophs are exclusively microorganisms; no known macrofauna possesses the ability to use inorganic compounds as electron sources. Macrofauna and lithotrophs can form symbiotic relationships, in which case the lithotrophs are called "prokaryotic symbionts". An example of this is chemolithotrophic bacteria in giant tube worms or plastids, which are organelles within plant cells that may have evolved from photolithotrophic cyanobacteria-like organisms. Chemolithotrophs belong to the domains Bacteria and Archaea. The term "lithotroph" was created from the Greek terms 'lithos' (rock) and 'troph' (consumer), meaning "eaters of rock". Many but not all lithoautotrophs are extremophiles.
Beggiatoa is a genus of Gammaproteobacteria belonging to the order Thiotrichales, in the Pseudomonadota phylum. These bacteria form colorless filaments composed of cells that can be up to 200 μm in diameter, and are one of the largest prokaryotes on Earth. Beggiatoa are chemolithotrophic sulfur-oxidizers, using reduced sulfur species as an energy source. They live in sulfur-rich environments such as soil, both marine and freshwater, in the deep sea hydrothermal vents, and in polluted marine environments. In association with other sulfur bacteria, e.g. Thiothrix, they can form biofilms that are visible to the naked eye as mats of long white filaments; the white color is due to sulfur globules stored inside the cells.
Microbial metabolism is the means by which a microbe obtains the energy and nutrients it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe's ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles.
A lithoautotroph is an organism which derives energy from reactions of reduced compounds of mineral (inorganic) origin. Two types of lithoautotrophs are distinguished by their energy source; photolithoautotrophs derive their energy from light while chemolithoautotrophs (chemolithotrophs or chemoautotrophs) derive their energy from chemical reactions. Chemolithoautotrophs are exclusively microbes. Photolithoautotrophs include macroflora such as plants; these do not possess the ability to use mineral sources of reduced compounds for energy. Most chemolithoautotrophs belong to the domain Bacteria, while some belong to the domain Archaea. Lithoautotrophic bacteria can only use inorganic molecules as substrates in their energy-releasing reactions. The term "lithotroph" is from Greek lithos (λίθος) meaning "rock" and trōphos (τροφοσ) meaning "consumer"; literally, it may be read "eaters of rock". The "lithotroph" part of the name refers to the fact that these organisms use inorganic elements/compounds as their electron source, while the "autotroph" part of the name refers to their carbon source being CO2. Many lithoautotrophs are extremophiles, but this is not universally so, and some can be found to be the cause of acid mine drainage.
CandidatusDesulforudis audaxviator is a species of bacterium that lives in groundwater at depths from 1.5–3 kilometres (0.93–1.86 mi) below the Earth's surface. The genus is monospecific.
Sulfur is metabolized by all organisms, from bacteria and archaea to plants and animals. Sulfur can have an oxidation state from -2 to +6 and is reduced or oxidized by a diverse range of organisms. The element is present in proteins, sulfate esters of polysaccharides, steroids, phenols, and sulfur-containing coenzymes.
An autotroph is an organism that can convert abiotic sources of energy into energy stored in organic compounds, which can be used by other organisms. Autotrophs produce complex organic compounds using carbon from simple substances such as carbon dioxide, generally using energy from light or inorganic chemical reactions. Autotrophs do not need a living source of carbon or energy and are the producers in a food chain, such as plants on land or algae in water. Autotrophs can reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide.
Sulfurimonas is a bacterial genus within the class of Campylobacterota, known for reducing nitrate, oxidizing both sulfur and hydrogen, and containing Group IV hydrogenases. This genus consists of four species: Sulfurimonas autorophica, Sulfurimonas denitrificans, Sulfurimonas gotlandica, and Sulfurimonas paralvinellae. The genus' name is derived from "sulfur" in Latin and "monas" from Greek, together meaning a “sulfur-oxidizing rod”. The size of the bacteria varies between about 1.5-2.5 μm in length and 0.5-1.0 μm in width. Members of the genus Sulfurimonas are found in a variety of different environments which include deep sea-vents, marine sediments, and terrestrial habitats. Their ability to survive in extreme conditions is attributed to multiple copies of one enzyme. Phylogenetic analysis suggests that members of the genus Sulfurimonas have limited dispersal ability and its speciation was affected by geographical isolation rather than hydrothermal composition. Deep ocean currents affect the dispersal of Sulfurimonas spp., influencing its speciation. As shown in the MLSA report of deep-sea hydrothermal vents Campylobacterota, Sulfurimonas has a higher dispersal capability compared with deep sea hydrothermal vent thermophiles, indicating allopatric speciation.
Desulfobulbus propionicus is a Gram-negative, anaerobic chemoorganotroph. Three separate strains have been identified: 1pr3T, 2pr4, and 3pr10. It is also the first pure culture example of successful disproportionation of elemental sulfur to sulfate and sulfide. Desulfobulbus propionicus has the potential to produce free energy and chemical products.
Desulfovibrio alkalitolerans is an alkalitolerant and sulfate-reducing bacterium of the genus of Desulfovibrio which has been isolated from a biofilm in a district heating plant in Skanderborg, Denmark. The isolation was from biofilm growing in alkaline water where there was corrosion of pipes in the heating plant.
Microbial oxidation of sulfur is the oxidation of sulfur by microorganisms to build their structural components. The oxidation of inorganic compounds is the strategy primarily used by chemolithotrophic microorganisms to obtain energy to survive, grow and reproduce. Some inorganic forms of reduced sulfur, mainly sulfide (H2S/HS−) and elemental sulfur (S0), can be oxidized by chemolithotrophic sulfur-oxidizing prokaryotes, usually coupled to the reduction of oxygen (O2) or nitrate (NO3−). Anaerobic sulfur oxidizers include photolithoautotrophs that obtain their energy from sunlight, hydrogen from sulfide, and carbon from carbon dioxide (CO2).