Development of a new method for detecting acetic acid bacteria in wine
The presence of acetic acid bacteria in wine can lead to the appearance of acetic acid at concentrations above the perception threshold, causing the wine rejection by the consumer. During the winemaking process, avoiding the presence of acetic acid bacteria is very difficult, as there is always a residual population accompanying the wine, and the problem arises with the significant development of these microorganisms that metabolizes large amounts of acetic acid.
The concern of wineries to control the presence of acetic acid bacteria in wines during their conservation is due to the absence of simple and effective analyses that allow the detection of these microorganisms in the initial stages. The aim of this study was to develop a liquid culture medium for the early detection of acetic acid bacteria based on olfactometry.
The culture medium was designed by modifying a previously existing one for the detection of acetic acid bacteria. For this purpose, the nutrient content was modified to enhance the development of these microorganisms, and their selectivity was increased. The efficacy of the medium was studied by seeding it with pure cultures and with mixtures of microorganisms of different species, and with wines artificially contaminated. Finally, the medium was validated by using it both in the laboratory and in wineries, with wines of different types and origins. It was possible to establish a correlation between the initial concentration of acetic acid bacteria and the time of appearance of detectable levels of acetic acid in the medium by olfactometry.
Acknowledgements: Laboratorios Dolmar Tentamus for the help provided
1) Bartowsky E.J. et al. (2008) Acetic acid bacteria spoilage of bottled red wine. A review. Int. J. Food Microbiol., 125: 60-70, DOI: 10.1016/j.ijfoodmicro.2007.10.016
2) Rodrigues N. et al. (2015) Development and use of a new medium to detect yeasts of the genera Dekkera/Brettanomyces. J. Appl. Microbiol., 90: 588-599, DOI: 10.1046/j.1365-2672.2001.01275.x.
Issue: ICGWS 2023
1Laboratorio Dolmar Tentamus, Paraje Micalanda, 26221 Gimileo, La Rioja, Spain
2ICVV, Instituto de Ciencias de la Vid y del Vino (Universidad de La Rioja, Gobierno de La Rioja and CSIC), Finca La Grajera, Ctra. Burgos km 6, 26007 Logroño (La Rioja), Spain
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acetic acid bacteria, acetic acid, olfactometry, wine