Molecular analysis of Oenococcus oeni population dynamics and the effect of aeration and temperature during alcoholic fermentation on malolactic fermentation

Summary The effects of aeration and temperature during alcoholic fermentation (AF) on spontaneous and inoculated malolactic fermentation (MLF) of wine have been analysed by following the population dynamics of Oenococcus oeni strains with multiplex random amplified polymorphic DNA-polymerase chain reaction. It has enabled us to follow precisely the proportion of different autochthonous strains and the starter strain through fermentations. Lack of aeration led to delays in AF, which meant that autochthonous lactic acid bacteria could develop earlier and prevented the starter strain from developing correctly. Temperature was not found to lead to any differences. Two strains were isolated in the same spontaneous MLF, suggesting that, in some cases, multiple strains might be responsible for the degradation of malic acid in wine. It can be concluded that delays in the AF can negatively affect the control of MLF and that this can be studied by following the development of the different strains of O. oeni.