Biocompatibility in Ternary Fermentations With Lachancea thermotolerans, Other Non-Saccharomyces and Saccharomyces cerevisiae to Control pH and Improve the Sensory Profile of Wines From Warm Areas

Global warming is causing serious problems, especially, in warm regions, where musts with excess sugars and high pH produce wines with decreased freshness and unstable evolution. This study aimed to determine biocompatibility between yeast species, the capacity for microbiological acidification, and the aromatic profile produced in ternary fermentations in which Lachancea thermotolerans has been co-inoculated with Hanseniaspora vineae, Torulaspora delbrueckii, or Metschnikowia pulcherrima, and the fermentation process is subsequently completed with sequential inoculation of Saccharomyces cerevisiae. For this purpose, different cell culture media and instruments were used such as infrared spectroscopy, enzymatic autoanalyzer, chromatograph coupled with a flame ionization detector, spectrophotometric analysis, among others. The behavior of these yeasts was evaluated alone and in co-inoculation, always finishing the fermentation with sequential inoculation of S. cerevisiae, at a stable temperature of 16°C and with a low level of sulfites (25 mg/L) in white must. Significant results were obtained in terms of biocompatibility using population counts (CFU/ml) in differential plating media that permitted monitoring. Quantification of the five species was studied. Concerning acidification by L. thermotolerans in co-inoculations, we showed some metabolic interactions, such as the inhibition of acidification when H. vineae/L. thermotolerans were used, generating just over 0.13 g/L of lactic acid and, conversely, a synergistic effect when M. pulcherrima/L. thermotolerans were used, achieving 3.2 g/L of lactic acid and a reduction in pH of up to 0.33. A diminution in alcohol content higher than 0.6% v/v was observed in co-inoculation with the L. thermotolerans/M. pulcherrima yeasts, with total sugar consumption and very slow completion of fermentation in the inoculations with H. vineae and T. delbrueckii. The aromatic composition of the wines obtained was analyzed and a sensory evaluation conducted, and it was found that both L. thermotolerans and co-inoculations retained more aromatic esters over time and had a lower evolution toward the yellow tones typical of oxidation and that the best sensory evaluation was that of the Lt + Mp co-inoculation. Lachancea thermotolerans and co-inoculations produced wines with low levels of volatile acidity (<0.4 g/L). This work shows that good consortia strategies with binary and ternary fermentations of yeast strains can be a powerful bio-tool for producing more complex wines.

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Molecular Characterization and Enological Potential of A High Lactic Acid-Producing Lachancea thermotolerans Vineyard Strain

Foods ◽

10.3390/foods9050595 ◽

2020 ◽

Vol 9 (5) ◽

pp. 595 ◽

Cited By ~ 4

Author(s):

Georgios Sgouros ◽

Athanasios Mallouchos ◽

Maria-Evangelia Filippousi ◽

Georgios Banilas ◽

Aspasia Nisiotou

Keyword(s):

Climate Change ◽

Lactic Acid ◽

Molecular Mechanisms ◽

Lactic Acid Production ◽

Adh Genes ◽

Key Enzyme ◽

Sequential Inoculation ◽

High Production ◽

Grape Wine ◽

Lachancea Thermotolerans

Lactic acid production is an important feature of the yeast Lachancea thermotolerans that has gained increasing interest in winemaking. In particular, in light of climate change, the biological acidification and ethanol reduction by the use of selected yeast strains may counteract the effect of global warming in wines. Here, the enological potential of a high lactate-producing L. thermotolerans strain (P-HO1) in mixed fermentations with S. cerevisiae was examined. Among the different inoculation schemes evaluated, the most successful implantation of L. thermotolerans was accomplished by sequential inoculation of S. cerevisiae, i.e., at 1% vol. ethanol. P-HO1produced the highest levels of lactic acid ever recorded in mixed fermentations (10.4 g/L), increasing thereby the acidity and reducing ethanol by 1.6% vol. L. thermotolerans was also associated with increases in ethyl isobutyrate (strawberry aroma), free SO2, organoleptically perceived citric nuances and aftertaste. To start uncovering the molecular mechanisms of lactate biosynthesis in L. thermotolerans, the relative expressions of the three lactate dehydrogenase (LDH) paralogous genes, which encode the key enzyme for lactate biosynthesis, along with the alcohol dehydrogenase paralogs (ADHs) were determined. Present results point to the possible implication of LDH2, but not of other LDH or ADH genes, in the high production of lactic acid in certain strains at the expense of ethanol. Taken together, the important enological features of P-HO1 highlighted here, and potentially of other L. thermotolerans strains, indicate its great importance in modern winemaking, particularly in the light of the upcoming climate change and its consequences in the grape/wine system.

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A simple coloring method to distinguish colonies of the yeasts Lachancea thermotolerans and Saccharomyces cerevisiae on agar media

10.1101/2021.03.15.434753 ◽

2021 ◽

Author(s):

Chrats Melkonian ◽

Auke Haver ◽

Marijke Wagner ◽

Zakaria Kalmoua ◽

Anna-Sophia Hellmuth ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Quality Control ◽

Lactic Acid ◽

Quantitative Assessment ◽

Bromocresol Purple ◽

Alcohol Content ◽

Lower Alcohol ◽

Agar Media ◽

Lachancea Thermotolerans ◽

Wine Fermentations

AbstractThe yeast Lachancea thermotolerans converts consumed sugar partly to lactic acid instead of ethanol and is therefore used together with Saccharomyces cerevisiae to produce wines with a lower alcohol content. Being able to distinguish these yeasts is important for quality control and quantitative assessment of the contributions of both yeasts to wine fermentations. Commonly used methods to routinely distinguish these organisms are indirect or rely on commercial products of undisclosed composition. Here we describe that adding bromocresol purple to agar media induces Lachancea colonies to develop a brown color, whereas Saccharomyces colonies remain white.

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Impact of Lachancea thermotolerans strain and lactic acid concentration on Oenococcus oeni and malolactic fermentation in wine

OENO One ◽

10.20870/oeno-one.2021.55.2.4657 ◽

2021 ◽

Vol 55 (2) ◽

pp. 365-380

Author(s):

Emma C. Snyder ◽

Vladimir Jiranek ◽

Ana Hranilovic

Keyword(s):

Lactic Acid ◽

Alcoholic Fermentation ◽

Lactic Acid Production ◽

Malolactic Fermentation ◽

Oenococcus Oeni ◽

Inhibitory Effect ◽

Sequential Inoculation ◽

The Impact ◽

Lachancea Thermotolerans

The yeast Lachancea thermotolerans can produce lactic acid during alcoholic fermentation (AF) and thereby acidify wines with insufficient acidity. However, little is known about the impact of L. thermotolerans on Oenococcus oeni, the primary lactic acid bacterium used in malolactic fermentation (MLF). This study explored the impact of sequential cultures of L. thermotolerans and Saccharomyces cerevisiae on MLF performance in white and red wines. Four L. thermotolerans strains were tested in Sauvignon blanc with sequential S. cerevisiae inoculation, compared to an S. cerevisiae control and the initially un-inoculated treatments. The L. thermotolerans wines showed large differences in acidification, and progression of MLF depended on lactic acid production, even at controlled pH. The highest and lowest lactic acid producing strains were tested further in Merlot fermentations with both co-inoculated and sequentially inoculated O. oeni. The low lactic acid producing strain enabled successful MLF, even when this failed in the S. cerevisiae treatment, with dramatically quicker malic acid depletion in O. oeni co-inoculation than in sequential inoculation. In contrast, a high lactic acid producing strain inhibited MLF irrespective of the O. oeni inoculation strategy. In a follow-up experiment, increasing concentrations of exogenously added lactic acid slowed MLF and reduced O. oeni growth across different matrices, with 6 g/L of lactic acid completely inhibiting MLF. The results confirm the inhibitory effect of lactic acid on O. oeni while highlighting the potential of some L. thermotolerans strains to promote MLF and the others to inhibit it.

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Lachancea thermotolerans, the Non-Saccharomyces Yeast that Reduces the Volatile Acidity of Wines

Fermentation ◽

10.3390/fermentation4030056 ◽

2018 ◽

Vol 4 (3) ◽

pp. 56 ◽

Cited By ~ 18

Author(s):

Alice Vilela

Keyword(s):

Acetic Acid ◽

Lactic Acid ◽

Acid Production ◽

Lactic Acid Production ◽

High Concentration ◽

Volatile Acidity ◽

Saccharomyces Yeast ◽

Lachancea Thermotolerans

To improve the quality of fermented drinks, or more specifically, wine, some strains of yeast have been isolated, tested and studied, such as Saccharomyces and non-Saccharomyces. Some non-conventional yeasts present good fermentative capacities and are able to ferment in quite undesirable conditions, such as the case of must, or wines that have a high concentration of acetic acid. One of those yeasts is Lachancea thermotolerants (L. thermotolerans), which has been studied for its use in wine due to its ability to decrease pH through L-lactic acid production, giving the wines a pleasant acidity. This review focuses on the recent discovery of an interesting feature of L. thermotolerans—namely, its ability to decrease wines’ volatile acidity.

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Wine Fermentation Performance of Indigenous Saccharomyces cerevisiae and Saccharomyces paradoxus Strains Isolated in a Piedmont Vineyard

Beverages ◽

10.3390/beverages7020030 ◽

2021 ◽

Vol 7 (2) ◽

pp. 30

Author(s):

Antonella Costantini ◽

Maria Carla Cravero ◽

Loretta Panero ◽

Federica Bonello ◽

Enrico Vaudano ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Pilot Scale ◽

Sensory Profile ◽

Wine Quality ◽

Saccharomyces Paradoxus ◽

Volatile Acidity ◽

Trained Panel ◽

High Production ◽

Indigenous Yeasts

The role of yeast in wine quality is very important. The use of selected autochthonous yeasts is becoming more and more frequent in enology, not only to obtain a diversification of wines, but also as a link between the wine and its territory of origin. The objectives of this work were to test two indigenous yeasts in a cellar on a pilot scale. The yeasts were a strain of Saccharomyces cerevisiae and a strain of Saccharomyces paradoxus previously isolated in a vineyard in Piedmont (Italy). Studying the oenological characteristics of S. paradoxus is of particular interest, as it is rarely found in the cellar–vineyard environment. Molecular biology methods confirmed the predominance of the strain inoculated in the various fermentation tests. Additionally, products of yeast metabolism, including volatile compounds, were quantified at the end of the alcoholic fermentation and sensory profile of wines was tested by a trained panel of tasters. Our results indicated that both strains have good characteristics to be used as starter in winemaking; S. paradoxus was characterized by a high production of glycerol and the ability to degrade malic acid, together with a lower production of ethanol and a low volatile acidity, while S. cerevisiae conferred to the wine a pleasant smell of rose, as highlighted in the sessions of sensory analysis.

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Dynamic of Lachancea thermotolerans Population in Monoculture and Mixed Fermentations: Impact on Wine Characteristics

Beverages ◽

10.3390/beverages6020036 ◽

2020 ◽

Vol 6 (2) ◽

pp. 36

Author(s):

Pilar Blanco ◽

Eva Rabuñal ◽

Noemi Neira ◽

David Castrillo

Keyword(s):

Fatty Acids ◽

Population Dynamics ◽

Lactic Acid ◽

High Frequency ◽

Yeast Population ◽

Wild Yeast ◽

Wine Composition ◽

Sequential Inoculation ◽

Saccharomyces Yeast ◽

Lachancea Thermotolerans

Lachancea thermotolerans is a non-Saccharomyces yeast appreciated for its potential of acidification due to the production of lactic acid; however, this species also synthetizes other metabolites that modulate organoleptic wine properties. The aim of this study was to evaluate the strain L. thermotolerans Lt93 to ferment ‘Treixadura’ and ‘Mencía’ musts and its impact on yeast population dynamics and wine characteristics. Fermentations using monocultures of L. thermotolerans Lt93 and S. cerevisiae strains, sequential inoculation and spontaneous process were performed. The dynamic of yeast population and wine composition were analyzed following standard methodology. L. thermotolerans Lt93 was unable to overgrow wild yeast population in ‘Treixadura’ white must; however, with ‘Mencía’ red must, Lt93 was the predominant yeast at the beginning of fermentation and remained at high frequency until the end. Lt93 Treixadura wines had slightly higher acidity and higher content of esters and acids than ScXG3 wines. Lt93 Mencía wines presented higher acidity (10.1 g/L) and 0.8% (v/v) lower ethanol content than Sc71B wines. The content of esters and fatty acids was 3.3 and 4.0 times lower, respectively, in Lt93 than in Sc71B Mencía wines. It was possible to increase wine acidity and modulate the chemical wine profile by using Lt93.

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