Oenococcus oeni

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Oenococcus oeni
Oenococcus oeni

Oenococcus oeni

Systematics
Class : Bacilli
Order : Lactic acid bacteria (Lactobacillales)
Family : Leuconostocaceae
Genre : Oenococcus
Type : Oenococcus oeni
Scientific name
Oenococcus oeni
( Garvie 1967) Dicks et al. 1995

Oenococcus oeni is a gram-positive bacterium belonging to the order of the lactic acid bacteria (Lactobacillaceae). This bacterium wascountedto the genus Leuconostoc until 1995 , but is nowconsidered the only member of the genus Oenococcus alongside Oenococcus kitaharae and Oenococcus alcoholitolerans . These bacteria are characterized by lactic acid fermentation , a fermentative metabolism in which lactic acid occurs as the end product. Oenococcus oeni is, like all genera of the Leuconostocaceae family, obligate heterofermentative. In addition to lactic acid, other metabolic end products such as B. CO 2 , acetate (acetic acid) and ethanol (alcohol), while homofermentative lactic acid fermentation only produces lactic acid. Oenococcus oeni is usedby humansin winemaking.

features

Oenococcus oeni is acidophilic , so it grows well at low pH values . The cells are cocci-shaped . Oenococcus oeni tolerates large amounts of alcohol ( ethanol ) and can be cultivated in media with 10% ethanol.

Use by humans

Oenococcus oeni occurs naturally in fruit mash . This microorganism is used in wine production because it has the ability to convert malic acid into lactic acid through lactic acid fermentation ( malolactic fermentation ). This reduces the acidity of the wine, which gives it a milder taste.

Formation of diacetyl

Oenococcus oeni can form diacetyl from citrate , a compound with a typical butter taste. In small concentrations it contributes to the aroma, but in larger amounts it spoils the wine.

The metabolic pathway for the production of diacetyl from citrate or pyruvate . 1: citrate lyase 2: oxaloacetate decarboxylase 3: pyruvate decarboxylase 4: acetolactate synthase 5: acetolactate decarboxylase 6: oxidative decarboxylation 7: diacetyl reductase 8: acetoin reductase 9: diacetyl synthase, modified according to 10: transacetylase 11: pyruke Bartdec and 2004: Henscharke-Bartdec

Systematics and evolution

The genus Oenococcus forms together with Leuconostoc and Weissella the family Leuconostocaceae . These species are within the phylogeny , along with other genres such as Lactobacillus , Lactococcus , Enterococcus and Carnobacterium (all typical lactic acid bacteria ) to the so-called " Clostridium (English: branch" Clostridium branch) provided they are so closely related evolutionarily. In addition to Oenococcus oeni , the species Oenococcus kitaharae has been added to the genus Oenococcus since 2006 and the species Oenococcus alcoholitolerans since 2015 . The latter was first isolated from fermentation vats for cachaça in Brazil in 2014 and officially recognized as a new species within the genus a year later.

Oenococcus oeni is more distant on the phylogenetic branch due to 16s rRNA studies compared to species of Leuconostoc and Weisella and seems to vary more strongly in points of the rRNA that are more conserved in Weissella and Leuconostoc . Oenococus oeni thus seems to have a particularly rapid rate of evolution. This is called a tachytelic evolution rate, the opposite is the bradytelic rate, i.e. extremely slow changes in evolution. However, the assumption of a tachytellic evolution rate in Oenococcus oeni has again been questioned

swell

  1. ↑ EJ Bartowsky, PA Henschke: The 'buttery' attribute of wine - diacetyl - desirability, spoilage and beyond . In: Int. J. Food Microbiol. tape 96 , no. 3 , November 2004, p. 235-52 , doi : 10.1016 / j.ijfoodmicro.2004.05.013 , PMID 15454314 .
  2. ↑ JP Euzéby: List of Prokaryotic Names with Standing in Nomenclature. Genus Oenococcus ( Memento from May 5, 2008 in the Internet Archive )
  3. ↑ Fernanda Badotti, Ana Paula B. Moreira, Luciane A. Chimetto Tonon, Brígida T. Luckwu de Lucena, Fátima de Cássia O. Gomes: Oenococcus alcoholitolerans sp. nov., a lactic acid bacteria isolated from cachaça and ethanol fermentation processes . In: Antonie van Leeuwenhoek . tape 106 , no. 6 , October 15, 2014, ISSN  0003-6072 , p. 1259–1267 , doi : 10.1007 / s10482-014-0296-z ( springer.com [accessed November 1, 2016]).
  4. ↑ Aharon Oren, George M. Garrity: List of new names and new combinations previously effectively, but not validly, published . In: International Journal of Systematic and Evolutionary Microbiology . tape 65 , no. 4 , 1 January 2015 S. 1105–1111 , doi : 10.1099 / ijs.0.000178 ( microbiologyresearch.org [accessed November 1, 2016]).
  5. ^ D. Yang, CR Woese: Phylogenic structure of the “leuconostocs”: An interesting case of a rapidly evolving organism. In: Syst. Appl. Microbiol. Volume 12, 1989, pp. 145-149.
  6. ^ 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. Volume 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: Firmicutes, Cyanobacteria. Vol. 4: Bacteria: Firmicutes, cyanobacteria. 3. Edition. Springer-Verlag, New York 2006, ISBN 0-387-25494-3 , pp. 267-319.