EFFECT OF PHYSICOCHEMICAL FACTORS ON GLYCEROL PRODUCTION BY SIMULTANEOUS CULTURES OF WINE MICROORGANISMS USING A SURFACE RESPONSE METHOD

ALE, C. E.; BRU, E.; STRASSER DE SAAD, A.M.; PASTERIS, S.E.

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2014 vol. 117 p. 1336 - 1347

1364-5072

Aim: To evaluate the effect of temperature, pH and SO2 on growth and glycerol production improvement by Saccharomyces cerevisiae mc2, Kloeckera apiculata mF and Oenococcus oeni X2L using the Response Surface Method (RSM). Methods and Results: Multifactorial design of cultures with physicochemical factors variations was performed. The microorganisms grew in all cultures conditions. Overall, after 6 days yeasts prevailed, especially S. cerevisiae (109 cfu ml-1), while O. oeni reached 107 cfu ml-1. At initial fixed pH 5.5, metabolic behavior of cultures showed a temperature-dependent response. Total malate consumption occurred at 26 °C, 50 mg l-1 SO2. Glucose and pentoses utilization was highly modified when varying SO2. Ethanol showed negative interaction with temperature-SO2 relationship. At low SO2, glycerol and acetate production increased when temperature enhanced. Predictive results of RSM indicate that 26 ºC, 60.24 mg l-1 SO2, pH 5.5 was the optimal condition for glycerol and organic acids synthesis compatible with wine quality. Conclusions: We propose a predictive condition to improve the performance of mixed cultures for must fermentations. Significance and Impact of Study: To optimize the culture conditions to design mixed starters containing autochthonous yeasts and O. oeni strains for winemaking, to obtain products with high glycerol content, low acidity and maintenance of regional characteristics.