''Komagataeibacter xylinus'' is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

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 am ...

best known for its ability to produce

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

, specifically bacterial cellulose.

History and taxonomy

The species was first described in 1886 by Adrian John Brown, who identified the bacteria while studying fermentation. Brown gave the species the name ''Bacterium xylinum''. It has since been known by several other names, mainly ''Acetobacter xylinum'' and ''Gluconacetobacter xylinus''. It was given its current name, with the establishment of the new

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

'' Komagataeibacter'', in 2012. It is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

of the genus.

Genome and metabolism

''K. xylinus'' is a member of the

acetic acid bacteria Acetic acid bacteria (AAB) are a group of Gram-negative bacteria which oxidize sugars or ethanol and produce acetic acid during fermentation. The acetic acid bacteria consist of 10 genera in the family Acetobacteraceae. Several species of acet ...

, a group of

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cell ...

bacteria that produce

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main componen ...

during fermentation. ''K. xylinus'' is unusual among the group in also producing

. Bacterial cellulose (also sometimes known as nanocellulose) is involved in the formation of

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. It is chemically identical to plant cellulose, but has distinct physical structure and properties. The

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 ...

of a cellulose-deficient strain of ''K. xylinus'' was sequenced in 2011, and followed by the genomes of cellulose-producing strains in 2014 and 2018. The first cellulose-producing strain had a genome consisting of one

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 ar ...

3.4 megabase pairs and five

plasmid 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; howev ...

s, of which one is a "megaplasmid" of about 330 kilobase pairs. Key genes related to cellulose production occur in the four-gene

operon In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo spli ...

''bcsABCD'', which codes for the four subunits of the cellulose synthase

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

. All four genes are required for efficient cellulose production ''in vivo'', although BcsA and BscB are sufficient ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and ...

''. Several other genes in the ''K. xylinus'' genome are also involved in cellulose production and regulation, including a

cellulase Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysacchar ...

enzyme.

Uses and significance

''K. xylinus'' was used for a long time as a model organism for the study of cellulose production in

plant Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...

s. It is also studied in its own right to explore bacterial

production, cell-cell communication, and other topics of interest. Production of bacterial cellulose for industrial uses has been the subject of extensive research, but is limited by productivity and scalability. ''Acetobacter xylinus'' is found to be the main microorganism in the culture of

Kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the culture; Latin name ''Medusomyces gisevii'') is a fermented, lightly effervescent, sweetened black tea drink commonly consumed for its purported health b ...

. ''K. xylinus'' is also traditionally used in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

for the production of jelly-like '' nata de piña'' and ''

nata de coco ''Nata de coco'', also marketed as coconut gel, is a chewy, translucent, jelly-like food produced by the fermentation of coconut water, which gels through the production of microbial cellulose by '' Komagataeibacter xylinus''. Originating i ...

'' desserts, made from

pineapple juice Pineapple juice is a liquid made from pressing the natural liquid from the pulp of the pineapple (a fruit from a tropical plant). Numerous pineapple varieties may be used to manufacture commercial pineapple juice, the most common of which are ...

and

coconut water Coconut water (also coconut juice) is the clear liquid inside coconuts (fruits of the coconut palm). In early development, it serves as a suspension for the endosperm of the coconut during the nuclear phase of development. As growth continu ...

, respectively. The former has been produced since the 18th century.

References

{{Taxonbar, from=Q25861011 Rhodospirillales Cellulose Bacteria described in 1886