AbstractIn the wine making process, the interactions between lactic acid bacteria (LAB), yeast and other wine microflora have an impact on the wine quality. In this study, we investigate the influence of the LABOenococcus oeniand the spoilage yeastBrettanomyces bruxellensison the microbial community of a Cabernet Sauvignon wine. We generated metagenomic datasets from inoculations of three strains ofB. bruxellensis, in combination with twoO. oenistrains, one with and one without cinnamoyl esterase activity. This esterase activity releases hydroxycinnamic acids (HCAs) that can subsequently be processed by someB. bruxellensisstrains able to generate off-flavor compounds. We evaluated the influence of theO. oeniandB. bruxellensison the microbial taxonomic and functional potential profile, particularly regarding off-flavor formation due to HCAs. We found that the effect on the microbial profiles depends oni) theO. oeniandB. bruxellensisstrains being combined andii) the abundance they reach in the final wine, which depends on certain unidentified conditions. We confirmed that the potential ofB. bruxellensisto produce off-flavor compounds from HCAs depends on the strain. Interestingly, the samples without microbial inoculants also had this potential, suggesting that native grape microbiota could also influence the levels of HCA. We also found that the presence ofB. bruxellensisdoes not interfere with the malolactic fermentation of the evaluatedO. oenistrains, which leads to a less acidic taste. We show that metagenomic approaches can help uncover the complex wine microbial community traits, such as flavor, impacted by the simultaneous presence ofO. oeniandB. bruxellensis.
New Insights Into Cinnamoyl Esterase Activity of Oenococcus oeni
