Aim: To evaluate the coumarate descarboxylase (CD) and vinylphenol reductase (VR) activities in Dekkera bruxellensis isolates and study their relationship to the growth rate, protein profile and random amplified polymorphic DNA (RAPD) molecular pattern. Methods and Results: CD and VR activities were quantified, as well, the growth rate, intracellular protein profile and molecular analysis (RAPD) were determined in 12 isolates of D. bruxellensis. All the isolates studied showed CD activity, but only some showed VR activity. Those isolates with the greatest growth rate did not present a different protein profile from the others. The FASC showed a relationship between RAPD molecular patterns and VR activity. Conclusion: CD activity is common to all of the D. bruxellensis isolates. This was not the case with VR activity, which was detected at a low percentage in the analysed micro-organisms. A correlation was observed between VR activity and the RAPD patterns. Significance and Impact of the Study: This is the first study that quantifies the CD and VR enzyme activities in D. bruxellensis, demonstrating that these activities are not present in all isolates of this yeast.

Dekkera bruxellensis is the major contaminant yeast in the wine industry worldwide. Here, we present the draft genome sequence of D. bruxellensisLAMAP

Currently, there is a worldwide trend toward the food consumption without the use of preservatives. For this reason, biocontrols have emerged as a natural option to replace preservatives. We identify and select native wine yeasts with antimicrobial activity (AA) that work against pathogenic bacteria of food importance. We evaluated the antimicrobial capacity of 103 yeast against Salmonella typhimurium, Listeria monocytogenes, and Escherichia coli, by measuring the growth inhibition. AA was qualitatively determined by measuring the inhibition zone diameter accompanied by death zone of target cells. Results revealed that nine yeast strains showed AA against the three pathogens, being mainly of the genera Pichia, Candida, and Saccharomyces. To determine the type of AA, the viability was assessed by the method of SYTOX Green®. The results suggest that yeast exhibit AA bactericidal type. Thus, the use of yeasts arises as a natural and safe for the biocontrol of bacterial growth alternative.

Brettanomyces bruxellensis has been described as the main contaminant yeast in wine production, due to its ability to convert the hydroxycinnamic acids naturally present in the grape phenolic derivatives, into volatile phenols. Currently, there are no studies in B. bruxellensis which explains the resistance mechanisms to hydroxycinnamic acids, and in particular to p-coumaric acid which is directly involved in alterations to wine. In this work, we performed a transcriptome analysis of B. bruxellensis LAMAP248rown in the presence and absence of p-coumaric acid during lag phase. Because of reported genetic variability among B. bruxellensis strains, to complement de novo assembly of the transcripts, we used the high-quality genome of B. bruxellensis AWRI1499, as well as the draft genomes of strains CBS2499 and0 g LAMAP2480. The results from the transcriptome analysis allowed us to propose a model in which the entrance of p-coumaric acid to the cell generates a generalized stress condition, in which the expression of proton pump and efflux of toxic compounds are induced. In addition, these mechanisms could be involved in the outflux of nitrogen compounds, such as amino acids, decreasing the overall concentration and triggering the expression of nitrogen metabolism genes.