Evaluation of behaviour of Lachancea thermotolerans biocontrol agents on grape fermentations

NALLY, M.C. (EQUAL CONTRIBUTION); PONSONE, M.L. (EQUAL CONTRIBUTION); PESCE, V.M.; TORO, M.E.; VAZQUEZ, F.; CHULZE, S.

LETTERS IN APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018 vol. 67 p. 89 - 96

0266-8254

Previous researches have showed that Lachancea thermotolerans strains RCKT4and RCKT5 inhibited the growth of Aspergillus. However, currently, there areno data on their nutritional preferences, as a possible substrate competitoragainst Saccharomyces cerevisiae, and their effects on fermentation. In thiswork, we observed that the biocontrol yeasts and S. cerevisiae BSc203, based onthe utilization of 16 carbonate sources, revealed significant differences in thenutritional profile (biocontrol yeasts NS:025, BSc203 NS:056). Lachanceathermotolerans strains did not occupy the same niche as that of BSc203(NOI:044). The biocontrol agents and BSc203 presented similar competitiveattitude in terms of the sugar, ethanol and sulphite tolerances. Duringfermentation, the biocontrol yeasts were found to tolerate up to 12% v/vethanol, 250 mg ml1 of total SO2 and 30° Brix sugar. In mixed cultures, L.thermotolerans strains did not negatively affect the growth of BSc203 and thewine quality, except when RCKT4 was initially inoculated at a high proportionin the mixed culture 1MSK4 (1%BSc203/99%RCKT4), resulting in a lowerproduction of CO2 and ethanol, in comparison with pure BSc203. RCKT5, at ahigh proportion, in 1MSK5 (1%BSc203/99%RCKT5) presented promisingoenological properties. This fermentation showed lower acetic acid contentsand higher total acidity than pure BSc203.