In condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter that is typically formed when a gas of bosons at very low densities is cooled to temperatures very close to absolute zero. Under such conditions, a large fraction of bosons occupy the lowest quantum state, at which point microscopic quantum mechanical phenomena, particularly wavefunction interference, become apparent macroscopically. A BEC is formed by cooling a gas of extremely low density to ultra-low temperatures.
Bacillus is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum Bacillota, with 266 named species. The term is also used to describe the shape (rod) of other so-shaped bacteria; and the plural Bacilli is the name of the class of bacteria to which this genus belongs. Bacillus species can be either obligate aerobes which are dependent on oxygen, or facultative anaerobes which can survive in the absence of oxygen. Cultured Bacillus species test positive for the enzyme catalase if oxygen has been used or is present.
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form, but it is not a true spore. It is a stripped-down, dormant form to which the bacterium can reduce itself. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. There are many reports of spores remaining viable over 10,000 years, and revival of spores millions of years old has been claimed. There is one report of viable spores of Bacillus marismortui in salt crystals approximately 250 million years old. When the environment becomes more favorable, the endospore can reactivate itself into a vegetative state. Most types of bacteria cannot change to the endospore form. Examples of bacterial species that can form endospores include Bacillus cereus, Bacillus anthracis, Bacillus thuringiensis, Clostridium botulinum, and Clostridium tetani.
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.
FtsZ is a protein encoded by the ftsZ gene that assembles into a ring at the future site of bacterial cell division. FtsZ is a prokaryotic homologue of the eukaryotic protein tubulin. The initials FtsZ mean "Filamenting temperature-sensitive mutant Z." The hypothesis was that cell division mutants of E. coli would grow as filaments due to the inability of the daughter cells to separate from one another. FtsZ is found in almost all bacteria, many archaea, all chloroplasts and some mitochondria, where it is essential for cell division. FtsZ assembles the cytoskeletal scaffold of the Z ring that, along with additional proteins, constricts to divide the cell in two.
Bacillus subtilis, known also as the hay bacillus or grass bacillus, is a Gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus Bacillus, B. subtilis is rod-shaped, and can form a tough, protective endospore, allowing it to tolerate extreme environmental conditions. B. subtilis has historically been classified as an obligate aerobe, though evidence exists that it is a facultative anaerobe. B. subtilis is considered the best studied Gram-positive bacterium and a model organism to study bacterial chromosome replication and cell differentiation. It is one of the bacterial champions in secreted enzyme production and used on an industrial scale by biotechnology companies.
Thiaminase is an enzyme that metabolizes or breaks down thiamine into two molecular parts. It is an antinutrient when consumed.
A magnon is a quasiparticle, a collective excitation of the electrons' spin structure in a crystal lattice. In the equivalent wave picture of quantum mechanics, a magnon can be viewed as a quantized spin wave. Magnons carry a fixed amount of energy and lattice momentum, and are spin-1, indicating they obey boson behavior.
RecA is a 38 kilodalton protein essential for the repair and maintenance of DNA. A RecA structural and functional homolog has been found in every species in which one has been seriously sought and serves as an archetype for this class of homologous DNA repair proteins. The homologous protein is called RAD51 in eukaryotes and RadA in archaea.
In the field of molecular biology the 6S RNA is a non-coding RNA that was one of the first to be identified and sequenced. What it does in the bacterial cell was unknown until recently. In the early 2000s scientists found out the function of 6S RNA to be as a regulator of sigma 70-dependent gene transcription. All bacterial RNA polymerases have a subunit called a sigma factor. The sigma factors are important because they control how DNA promoter binding and RNA transcription start sites. Sigma 70 was the first one to be discovered in Escherichia coli.
The signal recognition particle RNA, is part of the signal recognition particle (SRP) ribonucleoprotein complex. SRP recognizes the signal peptide and binds to the ribosome, halting protein synthesis. SRP-receptor is a protein that is embedded in a membrane, and which contains a transmembrane pore. When the SRP-ribosome complex binds to SRP-receptor, SRP releases the ribosome and drifts away. The ribosome resumes protein synthesis, but now the protein is moving through the SRP-receptor transmembrane pore.
POU is a family of proteins that have well-conserved homeodomains.
Bacillomycins are a group of antifungal polypeptide antibiotics isolated from Bacillus subtilis.
Roberto Kolter is Professor of Microbiology, Emeritus at Harvard Medical School, an author, and past president of the American Society for Microbiology. Kolter has been a professor at Harvard Medical School since 1983 and was Co-director of Harvard's Microbial Sciences Initiative from 2003-2018. During the 35-year term of the Kolter laboratory from 1983 to 2018, more than 130 graduate student and postdoctoral trainees explored an eclectic mix of topics gravitating around the study of microbes. Kolter is a fellow of the American Association for the Advancement of Science and of the American Academy of Microbiology.
Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Superfluidity occurs in two isotopes of helium when they are liquefied by cooling to cryogenic temperatures. It is also a property of various other exotic states of matter theorized to exist in astrophysics, high-energy physics, and theories of quantum gravity. The theory of superfluidity was developed by Soviet theoretical physicists Lev Landau and Isaak Khalatnikov.
Bacillus atrophaeus is a species of black-pigmented bacteria. Its type strain is NRRL NRS-213. B. atrophaeus strains have been used extensively in biomedicine as indicator strains for heat- and chemical-based decontamination regimens. Most of the strains in use are derivatives of a lineage of B. atrophaeus that originated at Camp Detrick in the 1950s, where many modern biocontainment procedures were developed. B. atrophaeus has historically been known by several other names, including B. globigii and B. subtilis var. niger. Modern phylogenetic analyses using multiple genetic methods have placed B. atrophaeus close to B. subtilis. Its original and still most prominent use is as a surrogate organism for pathogenic B. anthracis, beginning in the U.S. bio-weapons program, as its pigmentation readily facilitated discrimination from non-pigmented background organisms in environmental samples. Subsequent genomic and phenotypic analysis of strains derived from the Camp Detrick isolates revealed that they had been deliberately selected for strains that exhibited elevated rates of sporulation.
Bose–Einstein condensation can occur in quasiparticles, particles that are effective descriptions of collective excitations in materials. Some have integer spins and can be expected to obey Bose–Einstein statistics like traditional particles. Conditions for condensation of various quasiparticles have been predicted and observed. The topic continues to be an active field of study.
Cyclic di-AMP is a second messenger used in signal transduction in bacteria and archaea. It is present in many Gram-positive bacteria, some Gram-negative species, and archaea of the phylum euryarchaeota.
The Bacillus subtilis φ29 Holin Family is a group of transporters belonging to the Holin Superfamily IV. A representative list of members belonging to the φ29 holin family can be found in the Transporter Classification Database.
A proteolipid is a protein covalently linked to lipid molecules, which can be fatty acids, isoprenoids or sterols. The process of such a linkage is known as protein lipidation, and falls into the wider category of acylation and post-translational modification. Proteolipids are abundant in brain tissue, and are also present in many other animal and plant tissues. They are proteins covalenently bound to fatty acid chains, often granting them an interface for interacting with biological membranes. They are not to be confused with lipoproteins, a kind of spherical assembly made up of many molecules of lipids and some apolipoproteins.
