''Leuconostoc'' is a genus of

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. The Gram stain is ...

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 ...

, placed within the family of

Lactobacillaceae The ''Lactobacillaceae'' are a family of lactic acid bacteria. It is the only family in the lactic acid bacteria which includes homofermentative and heterofermentative organisms; in the ''Lactobacillaceae,'' the pathway used for hexose fermentati ...

. They are generally ovoid

cocci Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea ...

often forming chains. ''Leuconostoc'' spp. are intrinsically resistant to

vancomycin Vancomycin is a glycopeptide antibiotic medication used to treat certain bacterial infections. It is administered intravenously ( injection into a vein) to treat complicated skin infections, bloodstream infections, endocarditis, bone an ...

and are

catalase Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting ...

-negative (which distinguishes them from

staphylococci ''Staphylococcus'', from Ancient Greek σταφυλή (''staphulḗ''), meaning "bunch of grapes", and (''kókkos''), meaning "kernel" or " Kermes", is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillale ...

). All species within this genus are heterofermentative and are able to produce

dextran Dextran is a complex branched glucan (polysaccharide derived from the condensation of glucose), originally derived from wine. IUPAC defines dextrans as "Branched poly-α-d-glucosides of microbial origin having glycosidic bonds predominantly C-1 ...

from

sucrose Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined ...

. They are generally slime-forming. The name Leuconostoc comes from Greek adjective ''leukos'' meaning clear; and the word ''nostoc'' gelatinous colonies, Leuconostoc - colorless nostoc. Blamed for causing the 'stink' when creating a

sourdough starter Sourdough is a type of bread that uses the fermentation by naturally occurring yeast and lactobacillus bacteria to raise the dough. In addition to leavening the bread, the fermentation process produces lactic acid, which gives the bread its dis ...

, some species are also capable of causing human infection. Because they are an uncommon cause of disease in humans, standard commercial identification kits are often unable to identify the organism. ''Leuconostoc'' spp., along with other lactic acid bacteria such as ''

Pediococcus ''Pediococcus'' is a genus of gram-positive lactic acid bacteria, placed within the family of Lactobacillaceae. They usually occur in pairs or tetrads, and divide along two planes of symmetry, as do the other lactic acid cocci genera '' Aerococc ...

'' and ''

Lactobacillus ''Lactobacillus'' is a genus of gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metabolically div ...

'', are responsible for the

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 ...

cabbage Cabbage, comprising several cultivars of '' Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B.& ...

, making it

sauerkraut Sauerkraut (; , ) is finely cut raw cabbage that has been fermented by various lactic acid bacteria. It has a long shelf life and a distinctive sour flavor, both of which result from the lactic acid formed when the bacteria ferment the sugar ...

. In this process, fresh cabbage is fermented in a light

brine Brine (or briny water) is a high-concentration solution of salt (typically sodium chloride or calcium chloride) in water. In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawat ...

, where the sugars in the cabbage are transformed by lactofermentation to

lactic acid Lactic acid is an organic acid. It has the molecular formula C3H6O3. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as wel ...

which gives the cabbage a sour flavour and good keeping qualities. ''Leuconostoc'' spp. are similarly part of the symbiotic colonies of bacteria and yeast (

SCOBY Symbiotic culture of bacteria and yeast (SCOBY) is a culinary symbiosis, symbiotic fermentation Microbial food cultures, culture (Fermentation starter, starter) consisting of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast whic ...

) involved in the fermentation of

kefir Kefir ( ; alternative spellings: kephir or kefier; ; ; ) is a Fermented milk products, fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic SCOBY, symbiotic culture. It is prep ...

, a fermented milk beverage and

kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the Microbiological culture, culture; Latin name ''Medusomyces gisevii'') is a fermented beverage, fermented, effervescent, Sweetened beverage, sweetened black ...

, a fermented tea.

Species

The genus ''Leuconostoc'' comprises the following species: * '' Leuconostoc carnosum'' Shaw and Harding 1989 * '' Leuconostoc citreum'' Farrow ''et al''. 1989 * '' Leuconostoc falkenbergense'' Wu and Gu 2021 * '' Leuconostoc fallax'' Martinez-Murcia and Collins 1992 * "''Leuconostoc garlicum''" Kim ''et al''. 2002 * ''

Leuconostoc gasicomitatum Leuconostoc gelidum is a 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 t ...

'' Björkroth et al. 2001 * '' Leuconostoc gelidum'' Shaw and Harding 1989 * '' Leuconostoc holzapfelii'' De Bruyne ''et al''. 2007 * '' Leuconostoc inhae'' Kim ''et al''. 2003 * '' Leuconostoc kimchii'' Kim ''et al''. 2000 * '' Leuconostoc lactis'' Garvie 1960 (Approved Lists 1980) * '' Leuconostoc litchii'' Chen ''et al''. 2020 * ''

Leuconostoc mesenteroides ''Leuconostoc mesenteroides'' is a species of lactic acid bacteria associated with fermentation, under conditions of salinity and low temperatures (such as lactic acid production in fermented sausages). In some cases of vegetable and food storage ...

'' (Tsenkovskii 1878) van Tieghem 1878 (Approved Lists 1980) * '' Leuconostoc miyukkimchii'' Lee ''et al''. 2012 * '' Leuconostoc palmae'' Ehrmann ''et al''. 2009 * '' Leuconostoc pseudomesenteroides'' Farrow ''et al''. 1989 * '' Leuconostoc rapi'' Lyhs ''et al''. 2015 * '' Leuconostoc suionicum'' (Gu ''et al''. 2012) Jeon ''et al''. 2017

''Leuconostoc citrovorum''

The name ''Leuconostoc citrovorum'' (Hammer) Hucker and Pederson 1931 was rejected in 1971 as a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

'' by the Judicial Commission of

International Committee on Systematics of Prokaryotes The International Committee on Systematics of Prokaryotes (ICSP), formerly the International Committee on Systematic Bacteriology (ICSB), is the body that oversees the nomenclature of prokaryotes, determines the rules by which prokaryotes are named ...

(in Opinion 45).

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 Nomenclatu ...

and the phylogeny is based on whole-genome sequences.

References

External links

List of species of the genus ''Leuconostoc''

''Leuconostoc''
MicrobeWiki Lactobacillaceae Garde manger Bacteria used in dairy products Bacteria genera {{lactobacilli-stub