Comparasion of growth and metabolic characteristics of Brettanomyces yeast wine isolates

Kvasac Brettanomyces bruxellensis se smatra glavnim kontaminantom crnih vina. Ovaj kvasac djeluje negativno na senzorske karakteristike vina (miris, okus i boju) zbog proizvodnje hlapivih fenola, smanjenja boje crnih vina te povećanje hlapive kiselosti vina. Budući da vino kontaminirano kvascem B. bruxellensis nije poželjno za konzumaciju ovaj kvasac uzrokuje značajne ekonomske gubitke u svim vinarskim regijama svijeta. Cilj ovog istraživanja bio je ispitati razlike u rastu i metaboličkoj aktivnosti (proizvodnja hlapivih fenola i octene kiseline) vinskih izolata kvasca B. bruxellensis prisutnim u hrvatskim vinarskim regijama te usporediti s referetnim izolatom kvasca B. bruxellensis izoliranim iz vina u Francuskoj. Uzgoj vinskih izolata je proveden u semi-anaerobnim uvjetima u dvije podloge, općoj podlozi za rast kvasaca (YPD) i sintetskom modelnom vinu (SWM). Uočeno je kako rast izolata kao i metabolička aktivnost ovise o podlozi u kojoj se uzgajaju, ali i o samom izolatu. Brži rast i potrošnja hidroksicimetnih kiselina te veća proizvodnja hlapivih fenola i octene kiseline uočena je tijekom uzgoja izolata kvasca B. bruxellensis u YPD podlozi u odnosu na SWM.Brettanomyces bruxellensis yeast is considered as the main spoilage yeast of red wines. This yeast has negative impact on sensory wine characteristics (odor, flavor and color) because it produces volatile phenols and causes loss of colour in red wines and increase of volatile acidity in wine. It causes significant financial losses in all geographic wine regions in the world because wine contaminated by this yeast is not desirable for consumption. The aim of this study was to investigate diversity of growth and metabolic characteristics (production of volatile phenols and acetic acid) of B. bruxellensis wine isolates collected from Croatian wine regions and to compare them to the referent isolate collected from wine in France. Growth of the wine isolates was evaluated in two media, general medium for yeast growth (YPD) and synthetic wine medium (SWM), under semi-anaerobic conditions. It was determined that growth and metabolic activity of wine isolates depend on growth medium and also on the wine isolate itself. Faster growth and consumption of hydroxycinnamic acids and also higher production of volatile phenols and acetic acid were determined when B. bruxellensis wine isolates were grown in YPD medium than in SWM