Lysinibacillus sphaericus | |
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Scientific classification ![]() | |
Domain: | Bacteria |
Phylum: | Bacillota |
Class: | Bacilli |
Order: | Bacillales |
Family: | Bacillaceae |
Genus: | Lysinibacillus |
Species: | L. sphaericus |
Binomial name | |
Lysinibacillus sphaericus (Meyer and Neide 1904) Ahmed et al. 2007 | |
Lysinibacillus sphaericus (previously known as Bacillus sphaericus) [1] is a Gram-positive, mesophilic, rod-shaped bacterium commonly found on soil. It can form resistant endospores that are tolerant to high temperatures, chemicals and ultraviolet light and can remain viable for long periods of time. It is of particular interest to the World Health Organization due to the larvicide effect of some strains against two mosquito genera ( Culex and Anopheles ), [2] more effective than Bacillus thuringiensis , frequently used as a biological pest control. L. sphaericus cells in a vegetative state are also effective against Aedes aegypti larvae, [3] an important vector of yellow fever and dengue viruses.
A bacterium similar to this species was found in a 25-million-year-old amber from the Dominican Republic. The endospore was successfully revived. [4]
The reclassification from Bacillus sphaericus to Lysinibacillus sphaericus is based on the fact that the Lysinibacillus genus, in contrast to the type species of the genus Bacillus, contains peptidoglycan with lysine, aspartic acid, alanine and glutamic acid. [1]
L. sphaericus has five homology groups (I-V), with group II further dividing into subgroups IIA and IIB. [5] Even before full genomes were known, these groups were proposed to represent distinct species, due to the low levels of homology between groups. In 2015, genome-scale studies by Xu et al show that the current species is paraphyletic and subsumes L. fusiformis and L. boronitolerans. [6] GTDB's whole-genome comparison concurs in the need for splitting species. [7]
The entomopathogenic strains are found in the homology subgroup IIA, nonetheless, this group contains also non pathogenic isolates The insecticidal activity of some strains of L. sphaericus was first discovered in 1965 and further studies have shown mosquitoes to be the major target of this bacterium. There are reports of activity against other organisms such as the nematode Trichostrongylus colubriformis to which it has lethal effects on the eggs. [8] It is of important use in mosquito control programs worldwide and has high specificity against mosquito larvae in addition to being safe for mammals, fish, birds and nondipterean insects. [2]
The high toxicity strains produce during sporulation a binary toxin composed of BinA (42 kDa) and BinB (51 kDa) proteins, which is the major insecticidal component. The protein BinB acts by binding to a receptor in the epithelial midgut cells, facilitating the entrance of BinA which causes cellular lysis. [9] After being ingested by larvae, these proteins are solubilized in the gut and undergo proteolysis to active lower molecular weight derivatives. The vegetative cells of both high- and low-toxicity strains produce Mtx1, Mtx2 and Mtx3 toxins, but Mtx1 and Mtx2 are degraded by proteases during the stationary phase, consequently making them undetectable in sporulated cultures. [10] In addition, the presence of binary-toxin genes and proteins has been determined in 18 pathogenic strains. [11] Strains OT4b.2, OT4b.20, OT4b.25, OT4b.26 and OT4b.58 were found as toxic as the spores of the reference WHO strain 2362, against C. quinquefasciatus larvae. [12]
The bioremediation potential of L. sphaericus has been widely studied: strains with chromate reduction capacity have been isolated from different contaminated environments and naturally metal-rich soils. [13] The strain JG-A12, isolated from uranium-mining waste piles in Germany, is also able to reversibly bind aluminium, cadmium, copper, lead and uranium. [14] Different studies have shown that this ability is due to the presence of a proteinaceous surface covering these cells, called the S-layer, which is able to bind high quantities of heavy metals in saline solutions. [15] The biotechnological potential among Colombian isolates IV(4)10 and OT4b.31 showed heavy metal biosorption in living and dead biomass. [16] L. sphaericus strain CBAM5 showed resistance to 200 mM of arsenic which may be explained by the presence of the arsenate reductase gene. [17]
Bacillus thuringiensis is a gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide. B. thuringiensis also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic environments, animal feces, insect-rich environments, and flour mills and grain-storage facilities. It has also been observed to parasitize other moths such as Cadra calidella—in laboratory experiments working with C. calidella, many of the moths were diseased due to this parasite.
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.
Bacillus cereus is a Gram-positive rod-shaped bacterium commonly found in soil, food, and marine sponges. The specific name, cereus, meaning "waxy" in Latin, refers to the appearance of colonies grown on blood agar. Some strains are harmful to humans and cause foodborne illness due to their spore-forming nature, while other strains can be beneficial as probiotics for animals, and even exhibit mutualism with certain plants. B. cereus bacteria may be anaerobes or facultative anaerobes, and like other members of the genus Bacillus, can produce protective endospores. They have a wide range of virulence factors, including phospholipase C, cereulide, sphingomyelinase, metalloproteases, and cytotoxin K, many of which are regulated via quorum sensing. B. cereus strains exhibit flagellar motility.
Shigella is a genus of bacteria that is Gram-negative, facultatively anaerobic, non–spore-forming, nonmotile, rod-shaped, and is genetically closely related to Escherichia. The genus is named after Kiyoshi Shiga, who discovered it in 1897.
Bacillus thuringiensis serotype israelensis (Bti) is a group of bacteria used as biological control agents for larvae stages of certain dipterans. Bti produces toxins which are effective in killing various species of mosquitoes, fungus gnats, and blackflies, while having almost no effect on other organisms. The major advantage of B. thuringiensis products is that they are thought to affect few non-target species. However, even though Bti may have minimal direct effects on non-target organisms, it may potentially be associated with knock-on effects on food webs and other ecosystem properties, including biodiversity and ecosystem functioning.
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.
Aeromonas hydrophila is a heterotrophic, Gram-negative, rod-shaped bacterium mainly found in areas with a warm climate. This bacterium can be found in fresh or brackish water. It can survive in aerobic and anaerobic environments, and can digest materials such as gelatin and hemoglobin. A. hydrophila was isolated from humans and animals in the 1950s. It is the best known of the species of Aeromonas. It is resistant to most common antibiotics and cold temperatures and is oxidase- and indole-positive. Aeromonas hydrophila also has a symbiotic relationship as gut flora inside of certain leeches, such as Hirudo medicinalis.
Pore-forming proteins are usually produced by bacteria, and include a number of protein exotoxins but may also be produced by other organisms such as apple snails that produce perivitellin-2 or earthworms, who produce lysenin. They are frequently cytotoxic, as they create unregulated pores in the membrane of targeted cells.
Bacillus odysseyi is a Gram-positive, aerobic, rod-shaped, round-spore- and endospore-forming eubacterium of the genus Bacillus. This novel species was discovered by scientist Myron T. La Duc of NASA’s Biotechnology and Planetary Protection Group, a unit whose purpose is to clean and sterilize spacecraft so as not to have microorganisms contaminate other celestial bodies or foreign microorganisms contaminate Earth, on the surface of the Mars Odyssey in a clean room at the Jet Propulsion Laboratory in La Cañada Flintridge before the spacecraft was launched to space. La Duc named the bacterium Bacillus odysseyi sp. nov. after the Odyssey mission. It had apparently evolved to live in the sparse environment of a clean room, and its secondary spore coat makes it especially resistant to radiation.
Bacillus anthracis is a gram-positive and rod-shaped bacterium that causes anthrax, a deadly disease to livestock and, occasionally, to humans. It is the only permanent (obligate) pathogen within the genus Bacillus. Its infection is a type of zoonosis, as it is transmitted from animals to humans. It was discovered by a German physician Robert Koch in 1876, and became the first bacterium to be experimentally shown as a pathogen. The discovery was also the first scientific evidence for the germ theory of diseases.
Paraclostridium bifermentans, formerly known as Clostridium bifermentans and abbreviated CLOBI, is an anaerobic, motile, gram-positive bacterium.
Lysinibacillus fusiformis is a gram-positive, rod-shaped bacterium of the genus Lysinibacillus. Scientists have yet to completely characterize this microbe's pathogenic nature. Though little is known about this organism, several genome sequencing projects for various strains of L. fusiformis are currently underway.
Lysinibacillus boronitolerans is a spore-forming, Gram-positive, motile, rod-shaped and boron-tolerant bacterium with type strain 10aT.
Caenorhabditis elegans- microbe interactions are defined as any interaction that encompasses the association with microbes that temporarily or permanently live in or on the nematode C. elegans. The microbes can engage in a commensal, mutualistic or pathogenic interaction with the host. These include bacterial, viral, unicellular eukaryotic, and fungal interactions. In nature C. elegans harbours a diverse set of microbes. In contrast, C. elegans strains that are cultivated in laboratories for research purposes have lost the natural associated microbial communities and are commonly maintained on a single bacterial strain, Escherichia coli OP50. However, E. coli OP50 does not allow for reverse genetic screens because RNAi libraries have only been generated in strain HT115. This limits the ability to study bacterial effects on host phenotypes. The host microbe interactions of C. elegans are closely studied because of their orthologs in humans. Therefore, the better we understand the host interactions of C. elegans the better we can understand the host interactions within the human body.
Salibacterium is a genus of Gram-positive bacteria from the family of Bacillaceae. The type species is Salibacterium halotolerans.
Alkalihalobacillus is a genus of gram-positive or gram-variable rod-shaped bacteria in the family Bacillaceae from the order Bacillales. The type species of this genus is Alkalihalobacillus alcalophilus.
Mesobacillus is a genus of gram-positive or gram-variable, rod-shaped bacteria in the family Bacillaceae within the order Bacillales. The type species for this genus is Mesobacillus jeotgali.
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.
Alkalicoccus is a genus of Gram-Positive rod-shaped bacteria in the family Bacillaceae from the order Bacillales. The type species of this genus is Alkalicoccus saliphilus.
Lysinibacillus is a genus of bacteria from the family of Bacillaceae. Members of this genus, in contrast to the type species of the genus Bacillus, contains peptidoglycan with lysine, aspartic acid, alanine and glutamic acid.
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