Oenological compatibility of biocontrol yeasts applied to wine grapes

PRENDES, LUCIANA PAOLA; MERÍN, MARÍA GABRIELA; COURTEL, CLAIRE; MORALES, CARINA; GARAU, JULIANA; MORATA DE AMBROSINI, VILMA INÉS

Logroño, La Rioja

Congreso; II International Congress on Grapevine and Wine Sciences (2ICGWS); 2023

Instituto de Ciencias de la Vid y del Vino (ICVV)

Antagonistic yeasts applied to wine grapes must be compatible with the thereafter winemaking process, avoiding competition with the fermentative Saccharomyces cerevisiae or affecting wine flavour. Therefore, fifteen epiphytic yeasts (6 Metschnikowia sp., 6 Hanseniaspora uvarum, 3 Starmerella bacillaris) previously selected for its biocontrol ability against Alternaria on wine grapes were evaluate for possible competition with S. cerevisiae by the Niche Overlap Index (NOI) employing YNB agar media with 10 mM of 17 different carbonate sources present in wine grapes (proline, asparagine, alanine, glutamic acid, tirosine, arginine, lisine, methionine, glicine, malic acid, tartaric acid, fructose, melibiose, raffinose, rhamnose, sucrose, glucose). Also, acetic acid production in YPD-calcium carbonate agar medium, H2S production in Biggy agar medium and the production of “Brett” character or other odour defects in pasteurized must with p-coumaric acid were evaluated. As result, all Metschnikowia sp. strains showed coexistence with S. cerevisiae because the NOI (number of common carbon sources used by the two microorganisms/number of carbon sources used only by the antagonist) was