Identification of yeasts isolated from wine-related environments and capable of producing 4-ethylphenol

Abstract

The ability to produce 4-ethylphenol from the substrate p-coumaric acid in synthetic media was evaluated for several yeast species associated with wine production. Molar conversion rates as high as 90% were found by only Dekkera bruxellensis, D. anomala and by some unidentified strains isolated from wine-related environments. Other unidentified strains produced traces of 4-ethylphenol. All unidentified strains showed the same cultural characteristics as D. bruxellensis when grown on DBDM (Dekkera/Brettanomyces differential medium) agar. The determination of long-chain fatty acid compositions and the utilization of peptide nucleic acid (PNA) probes specific for D. bruxellensis showed that the unidentified strains did not belong to this species. Further identification, by restriction pattern generated from PCR-amplification of the 5.8S rRNA gene and the two internal transcribed spacers (ITS), assigned the unidentified strains to Candida cantarelli, C. wickerhamii, Debaryomyces hansenii, Kluyveromyces lactis and Pichia guilliermondii. However, only some strains of P. guilliermondii were capable of converting p-coumaric acid into 4-ethylphenol with efficiencies close to those observed in D. bruxellensis and D. anomala. r

A Case Study of Selected Volatile Phenols from Brettanomyces and Micronutrients Mn, Fe, Cu, Zn in Chianti Red Wines

“…A report relevant to red Bordeaux wines and published some two decades ago claimed that the aggregate detection threshold of ethylphenols or perception limit (PL) was 426 μg L -1 (Chatonnet, 1992) by employing a panel of twenty tasters that followed a procedure previously constructed by the same laboratory (Boidron, 1988). The two ethylphenols are mostly produced by the yeast Brettanomyces/Dekkera bruxellensis (Dias, 2003). The precursors are p-coumaric acid and ferulic acid for EtP and EtG, respectively (Pollnitz, 2000).…”

Non-Saccharomyces Killer Toxins: Possible Biocontrol Agents Against Brettanomyces in Wine?

“…4-ethylphenol and 4-ethylguaiacol (Chatonnet et al, 1995;Dias et al, 2003b). Red wines are particularly prone to the development of B. bruxellensis and the subsequent production of ethylphenols compared to white wines (Romano et al, 2008), due to Vitis vinifera red varietals that contain precursor phenolics, e.g.…”

“…and Zygosaccharomyces spp., which cannot produce ethylphenols due to the inactivity of their vinylphenol reductase enzyme (Chatonnet et al, 1995). Nevertheless, the production of vinylphenols and ethylphenols in wine is mainly attributed to B. bruxellensis, as both its phenolic acid decarboxylase and vinyl phenol reductase enzymes are active (Dias et al, 2003a;2003b;Harris et al, 2009;Granato et al, 2014). Over the years, several research teams have attempted to isolate these two enzymes and to characterise their properties (Godoy et al, 2008;Tchobanov et al, 2008;Benito et al, 2009;Godoy et al, 2009;Harris et al, 2009).…”

Caracterização e comportamento fermentativo de linhagens de Dekkera contaminantes da fermentação alcoólica

“…As leveduras Brettanomyces/Dekkera estão envolvidas na deterioração da cerveja e vinho, com a produção de compostos secundários (CHATONNET et al, 1992(CHATONNET et al, , 1995DIAS et al, 2003;EDLIN et al, 1995). Estas leveduras produzem grandes concentrações de ácidos voláteis, compostos fenólicos, sendo o 4-etil-fenol, um éster que contribui na composição de sabor e aroma dos vinhos, o mais proeminente.…”

“…As leveduras Brettanomyces/Dekkera estão envolvidas na deterioração da cerveja e vinho, com a produção de compostos secundários (CHATONNET et al, 1992(CHATONNET et al, , 1995EDLIN et al, 1995;DIAS et al, 2003). Em vinho, estas leveduras crescem tipicamente em baixos números depois do término da fermentação alcoólica e malolática, durante o envelhecimento em barris, tanques e garrafas.…”