A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, with an optimum growth range from 20 to 45 °C. The optimum growth temperature for these organisms is 37°C. The term is mainly applied to microorganisms. Organisms that prefer extreme environments are known as extremophiles. Mesophiles have diverse classifications, belonging to two domains: Bacteria, Archaea, and to kingdom Fungi of domain Eucarya. Mesophiles belonging to the domain Bacteria can either be gram-positive or gram-negative. Oxygen requirements for mesophiles can be aerobic or anaerobic. There are three basic shapes of mesophiles: coccus, bacillus, and spiral.
Clostridium perfringens is a Gram-positive, rod-shaped, anaerobic, spore-forming pathogenic bacterium of the genus Clostridium. C. perfringens is ever-present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates, insects, and soil. It has the shortest reported generation time of any organism at 6.3 minutes in thioglycolate medium.
Shigella dysenteriae is a species of the rod-shaped bacterial genus Shigella. Shigella species can cause shigellosis. Shigellae are Gram-negative, non-spore-forming, facultatively anaerobic, nonmotile bacteria. S. dysenteriae has the ability to invade and replicate in various species of epithelial cells and enterocytes.
Clostridium tetani is a common soil bacterium and the causative agent of tetanus. Vegetative cells of C. tetani are usually rod-shaped and up to 2.5 μm long, but they become enlarged and tennis racket- or drumstick-shaped when forming spores. C. tetani spores are extremely hardy and can be found globally in soil or in the gastrointestinal tract of animals. If inoculated into a wound, C. tetani can grow and produce a potent toxin, tetanospasmin, which interferes with motor neurons, causing tetanus. The toxin's action can be prevented with tetanus toxoid vaccines, which are often administered to children worldwide.
Clostridium beijerinckii is a gram positive, rod shaped, motile bacterium of the genus Clostridium. It has been isolated from feces and soil. Produces oval to subterminal spores. it is named after Martinus Beijerinck who is a Dutch bacteriologist.
Clostridium enterotoxins are toxins produced by Clostridium species.
Clostridium histolyticum is a species of bacteria found in feces and the soil. It is a motile, gram-positive, aerotolerant anaerobe. C. histolyticum is pathogenic in many species, including guinea pigs, mice, and rabbits, and humans. C. histolyticum has been shown to cause gas gangrene, often in association with other bacteria species.
Clostridium innocuum is an anaerobic, non-motile, gram-positive bacterium that reproduces by sporulation. While there are over 130 species of Clostridium, C. innocuum is the third most commonly isolated. Although it is not normally considered an aggressive human pathogen, it has been isolated in some disease processes. C. innocuum and other Clostridium line the oropharynx and gastrointestinal tract, and are considered normal gut flora.
Clostridium cadaveris is an enteric, gas-forming, motile, strictly anaerobic gram-positive bacterium of the genus Clostridium. First described by Klein in 1899, it was noted to be the most prominent bacteria during human decomposition; historically it was described as "putrefying flora".
Enterocloster clostridioformis, formerly known as Clostridium clostridioforme, is an anaerobic, motile, Gram-positive bacterium.
Clostridium phytofermentans is an obligately anaerobic, rod-shaped spore-forming, Gram-positive bacterium in the family Lachnospiraceae. It is a model organism of interest for its ability to rapidly ferment diverse plant polysaccharides including cellulose, hemicellulose, and pectin to ethanol, acetate, and hydrogen. The C. phytofermentans 4.8 Mb genome has been fully sequenced, revealing it contains over 170 enzymes in the CAZy database, though one hydrolase appears to be essential for degrading cellulose.
Caldicellulosiruptor bescii is a species of thermophilic, anaerobic cellulolytic bacteria. It was isolated from a geothermally heated freshwater pool in the Valley of Geysers on the Kamchatka Peninsula in Russia in 1990. The species was originally named Anaerocellum thermophilum, but reclassified in 2010, based on genomic data.
Acidobacterium capsulatum is a bacterium. It is an acidophilic chemoorganotrophic bacterium containing menaquinone. It is gram-negative, facultative anaerobic, mesophilic, non-spore-forming, capsulated, saccharolytic and rod-shaped. It is also motile by peritrichous flagella. Its type strain is JCM 7670.
Syntrophococcus sucromutans is a Gram-negative strictly anaerobic chemoorganotrophic Bacillota. These bacteria can be found forming small chains in the habitat where it was first isolated, the rumen of cows. It is the type strain of genus Syntrophococcus and it has an uncommon one-carbon metabolic pathway, forming acetate from formate as a product of sugar oxidation.
Clostridium autoethanogenum is an anaerobic bacterium that produces ethanol from carbon monoxide, in so-called syngas fermentation, being one of the few known microorganisms to do so. It is gram-positive, spore-forming, rod-like, motile, and was first isolated from rabbit feces. Its type strain is strain JA1-1. Its genome has been sequenced.
Symbiobacterium thermophilum is a symbiotic thermophile that depends on co-culture with a Bacillus strain for growth. It is Gram-negative and tryptophanase-positive, with type strain T(T). It is the type species of its genus. Symbiobacterium is related to the Gram-positive Bacillota and Actinomycetota, but belongs to a lineage that is distinct from both.S. thermophilum has a bacillus shaped cell structure with no flagella. This bacterium is located throughout the environment in soils and fertilizers.
Cryptobacterium curtum is a Gram-positive anaerobic rod bacteria isolated from human mouths.
Oscillibacter valericigenes is a species of mesophilic bacterium identified in the alimentary canal of Japanese Corbicula clams. It is Gram-negative and anaerobic, with a straight to slightly curved rod-like morphology, and is motile with petritrichous flagella. It was not observed in culture to form spores.
Propionispira raffinosivorans is a motile, obligate anaerobic, gram-negative bacteria. It was originally isolated from spoiled beer and believed to have some causative effect in beer spoilage. Since then, it has been taxonomically reclassified and proven to play a role in anaerobic beer spoilage, because of its production of acids, such as acetic and propionic acid, during fermentation
Vibrio aerogenes is a gram-negative organism that is rod-shaped and has a two-sheathed flagella that is found on one side of the cell that makes it motile. When it is grown on polypeptone-yeast (PY) plate medium, the colonies are usually round and flat. It is an organism that is mesophilic which means it likes temperatures that are between 20-45°C. In addition, it is facultatively anaerobic, which means it can survive with or without oxygen. This is a marine bacteria that is most commonly found in temperatures between 30°C and 35°C and pH 6-7. It requires Na+ to grow and this is what makes the marine environment a necessity for this organism. V. aerogenes can ferment glucose and a few other carbohydrates to yield organic acids.
