Search results for "Brettanomyces"
showing 10 items of 24 documents
Partial vinylphenol reductase purification and characterization from Brettanomyces bruxellensis
2008
International audience; Brettanomyces is the major microbial cause for wine spoilage worldwide and causes significant economic losses. The reasons are the production of ethylphenols that lead to an unpleasant taint described as 'phenolic odour'. Despite its economic importance, Brettanomyces has remained poorly studied at the metabolic level. The origin of the ethylphenol results from the conversion of vinylphenols in ethylphenol by Brettanomyces hydroxycinnamate decarboxylase. However, no information is available on the vinylphenol reductase responsible for the conversion of vinylphenols in ethylphenols. In this study, a vinylphenol reductase was partially purified from Brettanomyces bruxe…
Fungal biodiversity in a new winery and population dynamics in the winery (Saccharomyces cerevisiae) and in aging cellar (Brettanomyces bruxellensis)
2020
The interspecific fungal biodiversity (Illumina Mi-Seq) and the dynamics of Saccharomyces cerevisiae and Brettanomyces bruxellensis species were studied in a new winery and/or in 3 aging cellars, more specifically on the floor, the walls, the equipment and the outside of the barrels. In the new winery, an initial fungal consortium (yeasts and molds) is already present on all the winery environments before the arrival of the first harvest. This consortium consists of fungal genera such as Aureobasidium, Alternaria, Didymella and Filobasidium. These genera, that persist during two vintages, are not specific to the winery environment and seem to be adapted to natural or anthropic environments …
Microbial Dynamics between Yeasts and Acetic Acid Bacteria in Kombucha: Impacts on the Chemical Composition of the Beverage.
2020
Kombucha is a traditional low-alcoholic beverage made from sugared tea and transformed by a complex microbial consortium including yeasts and acetic acid bacteria (AAB). To study the microbial interactions and their impact on the chemical composition of the beverage, an experimental design with nine couples associating one yeast strain and one AAB strain isolated from original black tea kombucha was set up. Three yeast strains belonging to the genera Brettanomyces, Hanseniaspora, and Saccharomyces and three strains of Acetobacter and Komagataeibacter species were chosen. Monocultures in sugared tea were analyzed to determine their individual microbial behaviors. Then, cultivation of the ori…
Comparative morphological characteristics of three Brettanomyces bruxellensis wine strains in the presence/absence of sulfur dioxide
2016
International audience; The red wine spoilage yeast Brettanomyces bruxellensis has been the subject of numerous investigations. Some of these studies focused on spoilage mechanisms, sulfur dioxide tolerance and nutrient requirements. Pseudomycelium formation, although a striking feature of this species, has however been poorly investigated. Furthermore, literature regarding the induction mechanism of pseudomycelium formation in this yeast is limited and lacks clarity, as results published are contradictory. This study elucidates this phenomenon among strains from geographically different areas. Potential environmental cues were investigated, to attain a better understanding of this mechanis…
Etude et caractérisation de l'état " Viable mais Non Cultivable " chez Brettanomyces, une levure d'altération des vins : nouvel outil de détection et…
2011
The viable but not culturable (VBNC) state has been studied in detail in bacteria. It has been suggested that the VBNC state also exists in eukaryote cells, such as wine yeasts, including Brettanomyces in particular. We investigated the VBNC state in this yeast, focusing on the conditions for entry and exit, and the morphological and metabolic modifications associated with this state. We added sulfite (0.8 mg.L-1 molecular SO2) to induce the VBNC state. Increasing the pH of the medium inactivated the sulfite, allowing the cells to exit from the VBNC state and to become culturable again. In these conditions, we found that Brettanomyces VBNC cells were smaller than culturable cells, and that …
Viable But Not Culturable (VBNC) state of Brettanomyces bruxellensis in wine: New insights on molecular basis of VBNC behaviour using a transcriptomi…
2016
International audience; The spoilage potential of Brettanomyces bruxellensis in wine is strongly connected with the aptitude of this yeast to enter in a Viable But Non Culturable (VBNC) state when exposed to the harsh wine conditions. In this work, we characterized the VBNC behaviour of seven strains of B. bruxellensis representing a regional intraspecific biodiversity, reporting conclusive evidence for the assessment of VBNC as a strain-dependent character. The VBNC behaviour was monitored by fluorescein diacetate staining/flow cytometry for eleven days after addition of 0.4, 0.6, 0.8, 1 and 1.2 mg/L of molecular SO2 (entrance in the VBNC state) and after SO2 removal (exit from the VBNC st…
Evolution of microbiological and chemical parameters during red wine making with extended post-fermentation maceration.
2014
Abstract The aim of the present work was to investigate the microbiological, chemical, and sensory characteristics of red wine subjected to post-fermentation maceration that was extended to 90 days. For this purpose, the ‘Aglianico di Taurasi’ grape was used as a case study. The total yeast concentration increased until day 40 of maceration and decreased thereafter, whereas the concentration of lactic acid bacteria slightly increased. Dekkera/Brettanomyces spp. and acetic acid bacteria were not detected. The yeast community was composed of Saccharomyces cerevisiae, Zygosaccharomyces bisporus, Metschnikowia pulcherrima, Hanseniaspora guilliermondii, Hanseniaspora uvarum, Pichia guilliermondi…
Spoilage potential of Brettanomyces bruxellensis strains isolated from Italian wines
2018
Abstract Brettanomyces bruxellensis is an important wine spoilage agent. In this study a population of Brettanomyces strains isolated from Italian wines was thoroughly investigated to evaluate adaptability to wine conditions and spoilage potential. The presumptive isolates of Brettanomyces were identified at species level with 26S rRNA gene sequencing and species-specific PCR, and subsequently subjected to analysis of intra-species variability through the study of intron splice sites (ISS-PCR). Although, some strains were tracked in wines from different regions, extensive genetic biodiversity was observed within the B. bruxellensis population investigated. All strains were evaluated for the…
Diversité des Brettanomyces et de leur résistance au SO2. Les nouvelles avancées vers une meilleure gestion du SO2 en vinification.
2019
International audience; Des recherches ont été menées par le Groupe National « Lutte contre Brettanomyces » et plus particulièrement sur la relation SO2 et Brettanomyces bruxellensis afin d’approfondir les connaissances sur le comportement de la levure et d’apporter des données essentielles à une bonne gestion du risque.Une grande diversité de la levure Brettanomyces a été mise en évidence (identification de différents groupes génétiques) ainsi que des comportements différents vis-à-vis du SO2 : sensibles, tolérants ou résistant. Grâce à la mise au point d’un outil prédictif (TYP \ Brett), les professionnels pourront connaître le groupe génétique pour mieux intervenir.Ces travaux ont égalem…
Starter cultures as biocontrol strategy to prevent Brettanomyces bruxellensis proliferation in wine
2017
Brettanomyces bruxellensis is a common and significant wine spoilage microorganism. B. bruxellensis strains generally detain the molecular basis to produce compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols that derive from the sequential bioconversion of specific hydroxycinnamic acids such as ferulate and p-coumarate. Although B. bruxellensis can be detected at any stage of the winemaking process, it is typically isolated at the end of the alcoholic fermentation (AF), before the staring of the spontaneous malolactic fermentation (MLF) or during barrel aging. For this reason, the endemic diffusion of B. bruxellensis leads to c…