''Komagataeibacter xylinus'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

best known for its ability to produce

cellulose Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...

, specifically bacterial cellulose.

History and taxonomy

The species was first described in 1886 by Adrian John Brown, who identified the bacteria while studying

fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...

. 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 (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

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 Oxidation, oxidize sugars or ethanol and produce acetic acid during Aerobic fermentation, fermentation. The acetic acid bacteria consist of 10 genus, genera in the family Acet ...

, a group of

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

aerobic 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 compone ...

during

. ''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 is a Syntrophy, syntrophic Microbial consortium, community of microorganisms in which cell (biology), cells cell adhesion, stick to each other and often also to a surface. These adherent cells become embedded within a slimy ext ...

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

genome 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 genes, other functional regions of the genome such as ...

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 package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

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 and ...

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 splic ...

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

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

. 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'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

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

Uses and significance

''K. xylinus'' was used for a long time as a

model organism A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...

for the study of cellulose production in

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

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. ''K. xylinus'' is found to be the main microorganism in the culture of kombucha. ''K. xylinus'' is also traditionally used in the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

for the production of jelly-like '' nata de piña'' and '' nata de coco'' desserts, made from pineapple juice and

coconut water Coconut water (also coconut juice) is the clear liquid inside young 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 developm ...

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

References

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