Search results for "bruxellensis"
showing 10 items of 15 documents
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…
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…
Cells-qPCR as a direct quantitative PCR method to avoid microbial DNA extractions in grape musts and wines.
2017
A novel quantitative PCR assay called Cells-qPCR has been developed for the rapid detection and quantification of yeasts, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) directly from grape must and wine that does not require DNA extraction. The assay was tested on Brettanomyces bruxellensis, Saccharomyces cerevisiae, Lactobacillus plantarum, Oenococcus oeni, Acetobacter aceti and Gluconobacter oxydans in culture media, and in white and red grape musts and wines. Standard curves were constructed from DNA and cells for the six target species in all the matrices. Good efficiencies were obtained for both when comparing DNA and cells standard curves. No reaction inhibition was observe…
Use of autochthonous yeasts and bacteria in order to control Brettanomyces bruxellensis in wine
2017
Biocontrol strategies for the limitation of undesired microbial developments in foods and beverages represent a keystone toward the goal of more sustainable food systems. Brettanomyces bruxellensis is a wine spoilage microorganism that produces several compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols. To control the proliferation of this yeast, sulfur dioxide is commonly employed, but the efficiency of this compound depends on the B. bruxellensis strain; and it is subject to wine composition and may induce the entrance in a viable, but nonculturable state of yeasts. Moreover, it can also elicit allergic reactions in humans. …
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…
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…
Biodiversità genetica e fisiologica, potenziale alterativo, di una popolazione di B. bruxellensis isolata da vini italiani
2018
B. bruxellensis è il principale microrganismo alterativo in ambito enologico, in grado di deprezzare fortemente i vini nei quali dovesse svilupparsi. Questo lievito è da sempre diffuso in cantina, ma i cambiamenti ambientali e tecnologici intervenuti negli ultimi anni ne hanno accentuato la pericolosità. Un approfondimento riguardo alla biodiversità intrinseca alla specie B. bruxellensis, e dunque al suo potenziale alterativo, è necessario per ottimizzare le strategie di controllo.
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 …
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…
Quantification des Brettanomyces par qPCR
2017
International audience; Brettanomyces bruxellensis est une levure d’altération du vin avec de faibles besoins nutritionnels, résistante à l’éthanol et aux faibles pH, lui permettant une implantation en vin durant ou après la fermentation alcoolique (Conterno et al., 2006). B. bruxellensis est capable de produire des phénols volatils (éthyl-4-phénol, éthyl-4-gaïacol et éthyl-4-catéchol) (Oelofse et al., 2008). Ces molécules volatiles odorantes amènent un caractère phénolé et animal au vin connu sous le nom de « caractère Brett ». D’autres molécules (2-acétyltétrahydropyridine et 2-éthyltétrahydropyridine) produites par B. bruxellensis sont également responsables d’une déviation organoleptiqu…