''Exiguobacterium'' is a genus of

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 ...

and a member of the low GC phyla of

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 earl ...

. Collins'' et al''. first described the genus ''Exiguobacterium ''with the characterization of ''E. aurantiacum'' strain DSM6208T from an alkaline potato processing plant. It has been found in areas covering a wide range of temperatures (-12 °C—55 °C) including glaciers in

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

and hot springs in

Yellowstone Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...

, and has been isolated from ancient

permafrost Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface ...

in Siberia. This ability to survive in varying temperature extremes makes them an important area of study. Some strains in addition to dynamic thermal adaption are also halotolerant (up to 13% added NaCl added to the medium), can grow within a wide range of pH values (5-11), tolerate high levels of UV radiation, and heavy metal stress (including arsenic). ''Exiguobacterium'' are globally diverse organisms that are found in a variety of environments including

microbialite Microbialite is a benthic sedimentary deposit made of carbonate mud (particle diameter < 5 μm) that is formed with the mediation of microbes. The constituent carbonate mud is a type of

Thrombolite Thrombolites (from Ancient Greek θρόμβος ''thrómbos'' meaning " clot" and λῐ́θος ''líthos'' meaning "stone") are clotted accretionary structures formed in shallow water by the trapping, binding, and cementation of sedimentary g ...

from

Pavilion Lake Pavilion Lake is a freshwater lake located in Marble Canyon, British Columbia, Canada home to colonies of freshwater microbialites. Location and Local Communities It is located between the towns of Lillooet and Cache Creek (29.44 kilometres WNW, ...

, BC and

Stromatolites Stromatolites () or stromatoliths () are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). The ...

from Laguna Socompa, Argentina), ocean, freshwater lakes, Himalayan ice, Himalayan soil,

hydrothermal vent A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

brine shrimp ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia La ...

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

marine fish Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school. Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater f ...

and in microbial

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

s Seven

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

s from the genus have been completed as either complete (one circular

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

, with

plasmids A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; how ...

) or in a draft format (containing multiple unassembled

contigs A contig (from ''contiguous'') is a set of overlapping DNA segments that together represent a consensus region of DNA.Gregory, S. ''Contig Assembly''. Encyclopedia of Life Sciences, 2005. In bottom-up sequencing projects, a contig refers to ov ...

). A new species of ''Exiguobacterium chiriqhucha'' has been found to have global distribution in cold lakes from Greenland, Pavilion Lake BC, and Laguna Negra, Argentina. The 'Chiri qhucha' in Quechua means 'cold lake.' The study of Gutiérrez-Preciado et al. was confirmed by the completion of genomes two strains of ''Exiguobacterium chiriqhucha'' RW2 and GIC31. Phospholipid fatty acid analysis (PLFA) of varying temperatures in ''Exiguobacterium chiriqhucha'' strain RW2 results in major rearrangements of cellular membrane function which may allow for its temperature, pH and salinity adaptation.

Biodegradation of plastic

According to an article in the Stanford News Service, senior research engineer Wei-Min Wu reported in his article "Biodegradation and Mineralization of Polystyrene by Plastic-Eating Mealworms. 2. Role of Gut Microorganisms." that

mealworm Mealworms are the larval form of the yellow mealworm beetle, ''Tenebrio molitor'', a species of darkling beetle. Like all holometabolic insects, they go through four life stages: egg, larva, pupa, and adult. Larvae typically measure about or ...

s can survive on a diet of

polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a ...

when aided by strain YT2 of Exiguobacterium living in their gut.

Phylogeny

The currently accepted taxonomy is based on the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclature ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...

(NCBI)

References

{{Taxonbar, from=Q16981932 Extremophiles Bacteria genera Plastivores

Biodegradation of plastic

Phylogeny

See also

References