The impact of oxygen on the final alcohol content of wine fermented by a mixed starter culture

  1. Morales, P. 3
  2. Rojas, V. 23
  3. Quirós, M. 13
  4. Gonzalez, R. 3
  1. 1 Evolva Biotech A/S, Copenhagen Ø, Denmark
  2. 2 Universidad Autónoma de San Luis Potosí
    info

    Universidad Autónoma de San Luis Potosí

    San Luis Potosí, México

    ROR https://ror.org/000917t60

  3. 3 Instituto de Ciencias de la Vid y del Vino
    info

    Instituto de Ciencias de la Vid y del Vino

    Logroño, España

    ROR https://ror.org/01rm2sw78

Journal:
Applied Microbiology and Biotechnology

ISSN: 0175-7598

Year of publication: 2015

Volume: 99

Issue: 9

Pages: 3993-4003

Type: Article

DOI: 10.1007/s00253-014-6321-3 SCOPUS: 2-s2.0-84938201074 WoS: 000352818800021 GOOGLE SCHOLAR
Institutional repository: lock_openOpen access editor

Abstract

We have developed a wine fermentation procedure that takes advantage of the metabolic features of a previously characterized Metschnikowia pulcherrima strain in order to reduce ethanol production. It involves the use of M. pulcherrima/Saccharomyces cerevisiae mixed cultures, controlled oxygenation conditions during the first 48 h of fermentation, and anaerobic conditions thereafter. The influence of different oxygenation regimes and initial inoculum composition on yeast physiology and final ethanol content was studied. The impact of oxygenation on yeast physiology goes beyond the first aerated step and influences yields and survival rates during the anaerobic stage. The activity of M. pulcherrima in mixed oxygenated cultures resulted in a clear reduction in ethanol yield, as compared to S. cerevisiae. Despite relatively low initial cell numbers, S. cerevisiae always predominated in mixed cultures by the end of the fermentation process. Strain replacement was faster under low oxygenation levels. M. pulcherrima confers an additional advantage in terms of dissolved oxygen, which drops to zero after a few hours of culture, even under highly aerated conditions, and this holds true for mixed cultures. Alcohol reduction values about 3.7 % (v/v) were obtained for mixed cultures under high aeration, but they were associated to unacceptable volatile acidity levels. In contrast, under optimized conditions, only 0.35 g/L acetic acid was produced, for an alcohol reduction of 2.2 % (v/v), and almost null dissolved oxygen during the process.