Inoculation strategies of indigenous Patagonian yeasts for their potential use as cider starter cultures

VILCHEZ, B.; CURILEN, Y.; DEL MÓNACO S. M.

Los Cocos, Córdoba

Congreso; XVII Congreso Argentino de Microbiología General - SAMIGE 2022; 2022

Sociedad Argentina de Microbiología General, SAMIGE

In this study, the aptitude of native yeasts from the Patagonian region for apple juice fermentation was evaluated. Different inoculation strategies were assayed, using pure cultures of previously isolated Saccharomyces cerevisiae ScM16 y Pichia kudriavzevii ScP15 patagonian native yeasts, in air trap flasks at a laboratory scale. Assays involved pure cultures (M16 or P15), co-cultures with both yeasts simultaneously (CoC) and sequential cultures: M16 and P15 added at the fifth day of fermentation (M16→P15); P15 and M16 added at the seventh day of fermentation (P15→M16), all carried out at 17 y 20°C. In addition, pH variations were performed in the initial apple juice (pH 3,30 and pH 3,60). Fermentation kinetics were followed for CO2 production by weighting the flasks, besides viable cell count (UFC/mL) and molecular analysis for species identification (ITS PCR/RFLP). Growth profiles were adjusted to Gompertz modified equation and kinetic parameters were determined: maximum specific growth rate (μmax, h-1), maximum CO2 production (A, gr) and Lag phase extension (λ, h). The results obtained showed that M16 pure culture presented a better growth rate in fermentation (2,04±0,44 for M16; 0,97±0,22 for P15; 1,09±0,08 for CoC; 1,59±0,38 for P15→M16 and 0,64±0,29 for M16→P15; p