Clostridium botulinum is a gram-positive, rod-shaped, anaerobic, spore-forming, motile bacterium with the ability to produce the neurotoxin botulinum.
Sourdough or sourdough bread is a bread made by the fermentation of dough using wild lactobacillaceae and yeast. Lactic acid from fermentation imparts a sour taste and improves keeping qualities.
Clostridium is a genus of anaerobic, Gram-positive bacteria. Species of Clostridium inhabit soils and the intestinal tract of animals, including humans. This genus includes several significant human pathogens, including the causative agents of botulism and tetanus. It also formerly included an important cause of diarrhea, Clostridioides difficile, which was reclassified into the Clostridioides genus in 2016.
Clostridium perfringens is a Gram-positive, bacillus (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.
Lactococcus lactis is a gram-positive bacterium used extensively in the production of buttermilk and cheese, but has also become famous as the first genetically modified organism to be used alive for the treatment of human disease. L. lactis cells are cocci that group in pairs and short chains, and, depending on growth conditions, appear ovoid with a typical length of 0.5 - 1.5 µm. L. lactis does not produce spores (nonsporulating) and are not motile (nonmotile). They have a homofermentative metabolism, meaning they produce lactic acid from sugars. They've also been reported to produce exclusive L-(+)-lactic acid. However, reported D-(−)-lactic acid can be produced when cultured at low pH. The capability to produce lactic acid is one of the reasons why L. lactis is one of the most important microorganisms in the dairy industry. Based on its history in food fermentation, L. lactis has generally recognized as safe (GRAS) status, with few case reports of it being an opportunistic pathogen.
Agrobacterium tumefaciens is the causal agent of crown gall disease in over 140 species of eudicots. It is a rod-shaped, Gram-negative soil bacterium. Symptoms are caused by the insertion of a small segment of DNA, from a plasmid into the plant cell, which is incorporated at a semi-random location into the plant genome. Plant genomes can be engineered by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors.
Teicoplanin is an semisynthetic glycopeptide antibiotic with a spectrum of activity similar to vancomycin. Its mechanism of action is to inhibit bacterial cell wall peptidoglycan synthesis. It is used in the prophylaxis and treatment of serious infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and Enterococcus faecalis.
Clostridium acetobutylicum, ATCC 824, is a commercially valuable bacterium sometimes called the "Weizmann Organism", after Jewish Russian-born biochemist Chaim Weizmann. A senior lecturer at the University of Manchester, England, he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, acetone, ethanol, and n-butanol from starch. The method has been described since as the ABE process,, yielding 3 parts of acetone, 6 of n-butanol, and 1 of ethanol. Acetone was used in the important wartime task of casting cordite. The alcohols were used to produce vehicle fuels and synthetic rubber.
The rumen, also known as a paunch, is the largest stomach compartment in ruminants and the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. The rumen's microbial favoring environment allows it to serve as the primary site for microbial fermentation of ingested feed. The smaller part of the reticulorumen is the reticulum, which is fully continuous with the rumen, but differs from it with regard to the texture of its lining.
The hok/sok system is a postsegregational killing mechanism employed by the R1 plasmid in Escherichia coli. It was the first type I toxin-antitoxin pair to be identified through characterisation of a plasmid-stabilising locus. It is a type I system because the toxin is neutralised by a complementary RNA, rather than a partnered protein.
Fibrobacter succinogenes is a cellulolytic bacterium species in the genus Fibrobacter. It is present in the rumen of cattle. F. succinogenes is a gram negative, rod-shaped, obligate anaerobe that is a major contributor to cellulose digestion. Since its discovery in the 1950s, it has been studied for its role in herbivore digestion and cellulose fermentation, which can be utilized in biofuel production.
Autoinducers are signaling molecules that are produced in response to changes in cell-population density. As the density of quorum sensing bacterial cells increases so does the concentration of the autoinducer. Detection of signal molecules by bacteria acts as stimulation which leads to altered gene expression once the minimal threshold is reached. Quorum sensing is a phenomenon that allows both Gram-negative and Gram-positive bacteria to sense one another and to regulate a wide variety of physiological activities. Such activities include symbiosis, virulence, motility, antibiotic production, and biofilm formation. Autoinducers come in a number of different forms depending on the species, but the effect that they have is similar in many cases. Autoinducers allow bacteria to communicate both within and between different species. This communication alters gene expression and allows bacteria to mount coordinated responses to their environments, in a manner that is comparable to behavior and signaling in higher organisms. Not surprisingly, it has been suggested that quorum sensing may have been an important evolutionary milestone that ultimately gave rise to multicellular life forms.
Sakacins are bacteriocins produced by Lactobacillus sakei. They are often clustered with the other lactic acid bacteriocins. The best known sakacins are sakacin A, G, K, P, and Q. In particular, sakacin A and P have been well characterized.
Streptococcus equinus is a Gram-positive, nonhemolytic, nonpathogenic, lactic acid bacterium of the genus Streptococcus. It is the principal Streptococcus found in the alimentary canal of a horse, and makes up the majority of the bacterial flora in horse feces. Equivalence with Streptococcus bovis has been contested.
Butyrivibrio is a genus of bacteria in Class Clostridia. Bacteria of this genus are common in the gastrointestinal systems of many animals. Genus Butyrivibrio was first described by Bryant and Small (1956) as anaerobic, butyric acid-producing, curved rods. Butyrivibrio cells are small, typically 0.4 – 0.6 µm by 2 – 5 µm. They are motile, using a single polar or subpolar monotrichous flagellum. They are commonly found singly or in short chains but it is not unusual for them to form long chains. Despite historically being described as Gram-negative, their cell walls contain derivatives of teichoic acid, and electron microscopy indicates that bacteria of this genus have a Gram-positive cell wall type. It is thought that they appear Gram-negative when Gram stained because their cell walls thin to 12 to 18 nm as they reach stationary phase.
Hathewaya histolytica is a species of bacteria found in feces and the soil. It is a motile, gram-positive, aerotolerant anaerobe. H. histolytica is pathogenic in many species, including guinea pigs, mice, and rabbits, and humans. H. histolytica has been shown to cause gas gangrene, often in association with other bacteria species.
Limosilactobacillus pontis is a rod-shaped, Gram-positive facultatively anaerobic bacterium. Along with other Lactobacillus species, it is capable of converting sugars, such as lactose, into lactic acid. Limosilactobacillus pontis is classified under the phylum Bacillota, class Bacilli, and is a member of the family Lactobacillaceae and is found to be responsible for the fermentation of sourdough, along with many other Lactobacillus species. This microorganism produces lactic acid during the process of fermentation, which gives sourdough bread its characteristic sour taste.
Lactiplantibacillus fabifermentans is a member of the genus Lactiplantibacillus and a type of lactic acid bacteria (LAB), a group of Gram-positive bacteria that produce lactic acid as their major fermented end product and that are often involved in food fermentation. L. fabifermentans was proposed in 2009 as a new species, after the type strain LMG 24284T has been isolated from Ghanaian cocoa fermentation. Analysis of the 16S rRNA gene sequence demonstrated that this species is a member of the Lactobacillus plantarum species group but further analysis demonstrated that it is possible to differentiate it from the nearest neighbors by means of DNA-DNA hybridization experiments, pheS sequence analysis, whole-cell protein electrophoresis, fluorescent amplified fragment length polymorphism analysis and biochemical characterization.
The Coriobacteriia are a class of Gram-positive bacteria within the Actinomycetota phylum. Species within this group are nonsporulating, strict or facultative anaerobes that are capable of thriving in a diverse set of ecological niches. Gordonibacter species are the only members capable of motility by means of flagella within the class. Several species within the Coriobacteriia class have been implicated with human diseases that range in severity. Atopobium, Olsenella, and Cryptobacterium species have responsible for human oral infections including periodontitis, halitosis, and other endodontic infections. Eggerthella species have been associated with severe blood bacteraemia and ulcerative colitis.
Methanogens are a group of microorganisms that produce methane as a byproduct of their metabolism. They play an important role in the digestive system of ruminants. The digestive tract of ruminants contains four major parts: rumen, reticulum, omasum and abomasum. The food with saliva first passes to the rumen for breaking into smaller particles and then moves to the reticulum, where the food is broken into further smaller particles. Any indigestible particles are sent back to the rumen for rechewing. The majority of anaerobic microbes assisting the cellulose breakdown occupy the rumen and initiate the fermentation process. The animal absorbs the fatty acids, vitamins and nutrient content on passing the partially digested food from the rumen to the omasum. This decreases the pH level and initiates the release of enzymes for further breakdown of the food which later passes to the abomasum to absorb remaining nutrients before excretion. This process takes about 9–12 hours.
