Impact of different temperature profiles on simultaneous yeast and bacteria fermentation

Abstract

Purpose: The role of fermentation temperature was studied for its impact on the evolution of malolactic fermentation performed by simultaneous inoculum of yeast and bacteria in grape must. Results were discussed considering the different fermentative kinetics and the composition of obtained wines. Methods: Two strains of bacteria belonging to the O. oeni and L. plantarum species were inoculated 24 h after the beginning of the alcoholic fermentation in 2 grape musts having different acidic and sugar profiles. Fermentations were conducted at 3 different temperature profiles (16/22°C in 3 days, 18/24°C in 3 days, 22/32°C in 5 days). Evolution of microbiota was followed by flow cytometry and plate count. Chemical analysis of grape musts and wines were performed by instrumental approaches (FT-IR, enzymatic quantification of malic acid, GC-MS). Results: L. plantarum resulted more efficient in malic acid consumption in the entire set of tests. These results are unexpected because, generally, Lactobacillus has been reported to be more sensitive to an oenological environment than O. oeni. In our experiments, O. oeni resulted inhibited by the highest fermentation temperature profile, causing incomplete malic acid degradation. Similarly, S. cerevisiae showed a higher sensitivity to environmental limiting factors in respect to what is generally known. Differences in the chemical composition of wines were observed in relation to the bacteria strain and the temperature profile. However, the statistical treatment of data identified temperature as the main variable able to influence the features of wines. Conclusions: Simultaneous inoculum of yeast and bacteria in grape must is an alternative approach in the management of malolactic fermentation which showed some interesting features. However, it is necessary to consider that the dynamics of the microbial population are different to that observed in traditional winemaking and the environmental variables act against the microorganisms in a peculiar, and in certain cases unexpected, way.

Biodiversity of Oenological Lactic Acid Bacteria: Species- and Strain-Dependent Plus/Minus Effects on Wine Quality and Safety

“…to degrade the malic acid and potentially enhanced acetic acid production. These findings have been recently confirmed by Guzzon and coworkers [58]. They showed that the L. plantarum strain more efficiently carried out the MLF compared to O. oeni, since the latter species was inhibited by a high fermentation temperature with subsequent incomplete malic acid degradation.…”

Dynamic Modeling of the Impact of Temperature Changes on CO2 Production during Milk Fermentation in Batch Bioreactors

“…The derivation of a parametric mathematical model of the fermentation process, which also describes the influence of temperature changes on the time course of concentrations of microorganisms, substrate, and fermentation product, is a relatively new field. Although there are many studies showing the influence of temperature on the fermentation processes of different species, these are limited mainly to the observation and numerical evaluation of the influence of different (constant) temperatures on the course of the fermentation process and do not result in deriving a parametric mathematical model [15][16][17].…”

Ozonized Oleic Acid as a New Viticultural Treatment? Study of the Effect of LIQUENSO® Oxygenate on the Carpoplane Microbial Community and Wine Microorganisms Combining Metabarcoding and In Vitro Assays

“…Yeasts and Gram-positive lactic acid bacteria (LAB) are important drivers of the alcoholic and malolactic fermentations, as reviewed by Capozzi et al (2021) [17]. The effect of these organisms during fermentation depends on interspecific interactions [18][19][20], the fermentation temperature [20] and wine chemical parameters such as pH nutrient and oxygen availability [21][22][23][24][25]. Non-Saccharomyces yeasts are often referred to in the context of incomplete or sluggish fermentations and undesirable off-flavors [21,26].…”