|
Bacillus Nealsonii
''Bacillus nealsonii'' is a species of bacteria first isolated from a spacecraft-assembly facility. Its spores are γ-radiation resistant. It is Gram-positive, facultatively anaerobic, rod-shaped and produces endospores. Its type strain is FO-92T (=ATCC BAA-519T =DSM 15077T). This species has been recently transferred into the genus ''Niallia ''Niallia'' is a genus of Gram-Positive rod-shaped bacteria in the family '' Bacillaceae'' from the order '' Bacillales.'' The type species of this genus is ''Niallia circulans.'' Members of ''Niallia'' are previously species belonging to '' Ba ...''. The correct nomenclature is ''Niallia nealsonii.'' References Further reading * * * External links *LPSN [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillota
The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The name "Firmicutes" was derived from the Latin words for "tough skin," referring to the thick cell wall typical of bacteria in this phylum. Scientists once classified the Firmicutes to include all gram-positive bacteria, but have recently defined them to be of a core group of related forms called the low- G+C group, in contrast to the Actinomycetota. They have round cells, called cocci (singular coccus), or rod-like forms (bacillus). A few Firmicutes, such as ''Megasphaera'', ''Pectinatus'', ''Selenomonas'' and ''Zymophilus'', have a porous pseudo-outer membrane that causes them to stain gram-negative. Many Bacillota (Firmicutes) produce endospores, which are resistant to desiccation and can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacilli
Bacilli is a taxonomic class of bacteria that includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens such as ''Bacillus anthracis'' (the cause of anthrax). ''Bacilli'' are almost exclusively gram-positive bacteria. The name ''Bacillus'', capitalized and italicized, refers to a specific genus of bacteria. The name Bacilli, capitalized but not italicized, can also refer to a less specific taxonomic group of bacteria that includes two orders, one of which contains the genus ''Bacillus''. When the word is formatted with lowercase and not italicized, 'bacillus', it will most likely be referring to shape and not to the genus at all. Ambiguity Several related concepts make use of similar words, and the ambiguity can create considerable confusion. The term "''Bacillus''" (capitalized and italicized) is also the name of a genus (''Bacillus anthracis'') that, among many other genera, falls within the class Bacilli. The word "bacillus" (or its plur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillales
The Bacillales are an order of Gram-positive bacteria, placed within the Bacillota. Representative genera include ''Bacillus'', ''Listeria'' and ''Staphylococcus''. See also * List of bacteria genera * List of bacterial orders This article lists the orders of the Bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) and the phylogeny is based on 16S ... References Gram-positive bacteria Bacilli {{bacilli-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillaceae
The Bacillaceae are a family of gram-positive, heterotrophic, rod-shaped bacteria that may produce endospores. Motile members of this family are characterized by peritrichous flagella. Some Bacillaceae are aerobic, while others are facultative or strict anaerobes. Most are not pathogenic, but ''Bacillus'' species are known to cause disease in humans. Gram-variable cell wall Some Bacillaceae, such as the genera '' Filobacillus, Lentibacillus,'' and '' Halobacillus'', stain Gram-negative or Gram-variable, but are known to have a Gram-positive cell wall.Lim, J.M., Jeon, C.O., Song, S.M., and C.J. Kim. 2005''Pontibacillus chungwhensis gen. nov., sp. nov., a moderately halophilic Gram-positive bacterium from a solar saltern in Korea'' Int. J. Syst. Evol. Microbiol. 55:165-170. Nomenclature Taxa within this family are sometimes colloquially identified as bacilli. However, this term is ambiguous because it does not distinguish between class Bacilli, order Bacillales, family Bacilla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus
''Bacillus'' (Latin "stick") 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. ''Bacillus'' can reduce themselves to oval endospores and can remain in this dormant state for years. The endospore of one species from Morocco is reported to have survived being heated to 420 °C. Endospore formation is usually triggered by a lack of nutrients: the bacterium divides within its cell wall, and one side then engulfs the other. They are not true spores (i.e., not an offspring). Endospore formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote which develops into a new s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Radiation
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (), it imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation ''gamma rays'' based on their relatively strong penetration of matter; in 1900 he had already named two less penetrating types of decay radiation (discovered by Henri Becquerel) alpha rays and beta rays in ascending order of penetrating power. Gamma rays from radioactive decay are in the energy range from a few kiloelectronvolts (keV) to approximately 8 megaelectronvolts (MeV), corresponding to the typical energy levels in nuclei with reasonably long lifeti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain (saf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niallia
''Niallia'' is a genus of Gram-Positive rod-shaped bacteria in the family '' Bacillaceae'' from the order '' Bacillales.'' The type species of this genus is ''Niallia circulans.'' Members of ''Niallia'' are previously species belonging to '' Bacillus'', a genus that has long been recognized by the scientific community as displaying extensive polyphyly and phylogenetic heterogeneity due to the vague criteria previously used to assign species to this clade. Multiple studies using comparative phylogenetic analyses have been published in an attempt to clarify the evolutionary relationships between ''Bacillus'' species, resulting in the establishment of numerous novel genera such as '' Alkalihalobacillus'', ''Brevibacillus, Solibacillus'', ''Alicyclobacillus,'' ''Virgibacillus'' and ''Evansella''. In addition, the genus ''Bacillus'' has been restricted to only include species closely related to '' Bacillus subtilis'' and '' Bacillus cereus.'' The name ''Niallia'' was named after the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
