Pediococcus identification

Lonvaud-Funel, A., Guilloux, O, and Joyeaux, A. 1993. Isolation of a DNA probe for identification of glucan-producing Pediococcus damnosus in wines. J. Appl. Bacteriol. 74, 41-47. 

Aside from physical appearance and Gram-stain reaction, physiological tests for identification of LAB center, initially, on the differences between the two pathways of sugar utilization. Wine LAB include both heterofermenters and homofermenters. Leuconostoc oenos and its strains are hetero-fermentative, whereas Pediococcus is homofermentative and the lactobacilli may be found in both groups. 

De Bruyne K, Franz CM, Vancanneyt M, Schillinger U, Mozzi F, de Valdez GF, De Vuyst L, Vandamme P. Pecbococcus argentinicus sp. nov. from Argentinean fermented wheat flour and identification of Pediococcus species by pheS, rpoA and atpA sequence analysis. Int J Syst Evol Microbiol. 2008 58 2909-16. 

Table 4.3 lists the lactic acid bacteria most often encountered in grape must and wine. Oenococcus oeni is known for ensuring malolactic fermentation in the great majority of cases. So far, the strictly homofermentative lactobacilli of Group I have not been isolated in must or wine. The species are therefore divided into facultative and strict heterofermenters for lactobacilli and into homofermenters (Pediococcus) and heterofermenters (Leuconostoc) for cocci. It is likely that this classification will be modified—on one hand due to anticipated progress in the identification of new species in wine, and on the other hand dne to eventual reclassifications of lactobacilli in the gronps described above. 

These initial investigations permit bacterial identification at the genus level Lactobacillus by morphology, and Pediococcus and Leuconostoc by morphology and determination of their homofermentative or heterofermentative character. Classification at the species level makes use of the analysis of the fermentation profiles of a large number of sugars. 

At present in enology, two particular cases are analyzed in this manner strains of Pediococcus damnosus, responsible for ropiness disease, and strains which produce histamine, notably 0. oeni. Preliminary studies have shown that P. damnosus strains capable of synthesizing the ropy wine polysaccharide possess a supplementary plasmid, contrary to normal strains. The ropy character is linked to the presence of this plasmid. A fragment was cloned in E. coli and now constitutes the base material for preparing the probe. In this manner, colony hybridization permits the identification of ropy clones even when mixed with other Pediococcus clones or other species of bacteria. This method is routinely used to identify this undesirable population in the microflora of wines at the end of winemaking and during aging (Lonvaud-Funel et al, 1993). 

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