Leuconostocaceae

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Leuconostocaceae
Oenococcus oeni

Oenococcus oeni

Systematics
Domain : Bacteria (bacteria)
Department : Firmicutes
Class : Bacilli
Order : Lactic acid bacteria (Lactobacillales)
Family : Leuconostocaceae
Scientific name
Leuconostocaceae
Garrity et al. 2001

Leuconostocaceae form a family of gram-positive bacteria from the order Lactobacillales , the typical lactic acid bacteria . They do not form catalases (they are catalase-negative) and, like all representatives of the Firmicutes tribe , have a low GC content . They are facultatively anaerobic , i.e. H. relatively insensitive to oxygen. All of the three genera appear as mostly oval cocci , but rod-shaped cells are also found in the genus Weissella . Spore formation does not occur. Characteristic, as also for lactic acid bacteria in general, is the fermentative metabolic pathway ( lactic acid fermentation ), in which lactic acid is the end product. All genera of Leuconostocaceae are here obligately heterofermentative, i. H. in addition to lactic acid, there are also other metabolic end products such as B. CO 2 , acetate (acetic acid) and ethanol .

Occurrence

All representatives of Leuconostocaceae generally need nutrient-rich environments. The genera are often found in foods such as B. in milk and dairy products, meat and also in spoiled fish products. Other places where Leuconostoc and Weissella were found are decomposing plant remains and , more rarely, living plants. Leuconostoc seems to be the predominant genus among the lactic acid bacteria that occur on dead plant remains.

Systematics and phylogeny

Genera of this family are:

Through phylogenetic studies with the help of comparisons of the 16S rRNA and the 23S rRNA (sh ribosomal RNA ), different species of Leuconostoc were assigned to the genus Weissella and Leuconostoc oenos to the genus Oenococcus and later these three genera were combined in the family Leuconostocaceae. In phylogeny, Leuconostoc , Oenococcus and Weissella belong to the so-called " Clostridium branch". This branch (English: Clostridium branch) also includes genera of typical lactic acid bacteria such as Lactobacillus , Lactococcus , Enterococcus and Carnobacterium . These genera are therefore closely related in evolutionary terms. In 2006 another species was added to the genus Oenococcus , O. kitaharae Endo & Okada 2006.

The genus Oenococcus is interesting in connection with the rate of evolution. Based on the 16s rRNA comparisons, Oenococcus oeni appears to have a very rapid evolution rate. One speaks of a tachytelic as opposed to the slow, bradytelic evolution rate. Compared to the other two genera, Oenococcus oeni is further away on the branch of the phylogenetic tree . Oenococcus also varies more strongly with points of the rRNA that are more conserved in Weissella and Leuconostoc . However, this assumption was again doubted.

Importance to humans

All representatives of this family play a major role in food processing. Especially Leuconostoc in the manufacture of dairy products (sour milk, buttermilk, etc.). Leuconostoc is also important for making silage . Oenococcus plays the largest role among the lactic acid bacteria in winemaking. Malo-lactate fermentation (MLF) gives the wine a milder taste.

In the past, species of Leuconostoc could also cause considerable damage in the sugar industry through what is known as frog spawn fermentation . The description and naming of this genus by Van Tieghem in 1878 also resulted from the scientific investigation of these economic problems.

swell

  1. ^ JO Mundt, WF Graham, IE McCarty: Spherical Lactic Acid-producing Bacteria of Southern-grown Raw and Processed Vegetables. In: Applied microbiology. Volume 15, Number 6, November 1967, pp. 1303-1308, ISSN  0003-6919 . PMID 16349739 . PMC 547188 (free full text).
  2. ↑ JP Euzéby: List of Prokaryotic Names with Standing in Nomenclature. - As of April 23, 2018.
  3. ^ D. Yang, CR Woese: Phylogenic structure of the “leuconostocs”: An interesting case of a rapidly evolving organism. In: Syst. Appl. Microbiol. 12, 1989, pp. 145-149.
  4. ^ R. Morse, MD Collins, K. Ohanlon, S. Wallbanks, PT Richardson: Analysis of the beta 'subunit of DNA-dependent RNA polymerase does not support the hypothesis inferred from 16S rRNA analysis that Oenococcus oeni (formerly Leuconostoc oenos) is a tachytelic (fast-evolving) bacterium. In: International Journal of Systematic Bacteriology. 46, 1996, pp. 1004-1009.

literature

  • J. Björkroth, W. Holzapfel: Genera Leuconostoc, Oenococcus and Weissella. In: M. Dworkin (Ed.): The prokaryotes: a handbook on the biology of bacteria. Volume 4: Bacteria: Firmicutes, Cyanobacteria. 3. Edition. Springer-Verlag, New York, NY 2006, ISBN 0-387-25494-3 , pp. 267-319.