| Title: | Novel wine yeast with ARO4 and TYR1 mutations that overproduce 'floral' aroma compounds 2-phenylethanol and 2-phenylethyl acetate |
| Author(s): | Cordente AG; Solomon M; Schulkin A; Leigh Francis I; Barker A; Borneman AR; Curtin CD; |
| Address: | "The Australian Wine Research Institute, PO Box 197, Glen Osmond, SA, 5064, Australia. toni.garciacordente@awri.com.au. The Australian Wine Research Institute, PO Box 197, Glen Osmond, SA, 5064, Australia. MMR Research Worldwide Ltd, 104-110 Crowmarsh Battle Barns, Preston Crowmarsh, Wallingford, Oxfordshire, OX10 6SL, UK. Department of Food Science and Technology, Oregon State University, 100 Wiegand Hall, Corvallis, OR, 97331-6602, USA" |
| Journal Title: | Appl Microbiol Biotechnol |
| DOI: | 10.1007/s00253-018-9054-x |
| ISSN/ISBN: | 1432-0614 (Electronic) 0175-7598 (Linking) |
| Abstract: | "It is well established that the choice of yeast used to perform wine fermentation significantly influences the sensory attributes of wines; different yeast species and strains impart different profiles of esters, volatile fatty acids, higher alcohols, and volatile sulphur compounds. Indeed, choice of yeast remains one of the simplest means by which winemakers can modulate the sensory characteristics of wine. Consequently, there are more than 100 commercially available Saccharomyces cerevisiae wine yeast strains available, mostly derived by isolation from vineyards and successful fermentations. Nevertheless, some desirable characteristics such as 'rose' and 'floral' aromas in wine are not present amongst existing strains. Such aromas can be conferred from the higher alcohol 2-phenylethanol (2-PE) and its acetate ester, 2-phenylethyl acetate (2-PEA). These metabolites of the aromatic amino acid phenylalanine are present at concentrations below their aroma detection thresholds in many wines, so their contribution to wine style is often minimal. To increase the concentration of phenylalanine metabolites, natural and chemically mutagenised populations of a S. cerevisiae wine strain, AWRI796, were exposed to toxic analogues of phenylalanine. Resistant colonies were found to overproduce 2-PE and 2-PEA by up to 20-fold, which resulted in a significant increase in 'floral' aroma in pilot-scale white wines. Genome sequencing of these newly developed strains revealed mutations in two genes of the biosynthetic pathway of aromatic amino acids, ARO4 and TYR1, which were demonstrated to be responsible for the 2-PE overproduction phenotype" |
| Keywords: | "Acetates/*metabolism Amino Acids/genetics Biosynthetic Pathways Flowers Fungal Proteins/*genetics Genome, Fungal High-Throughput Nucleotide Sequencing *Mutation *Odorants Phenylethyl Alcohol/*analogs & derivatives/*metabolism Saccharomyces cerevisiae/gene;" |
| Notes: | "MedlineCordente, Antonio G Solomon, Mark Schulkin, Alex Leigh Francis, I Barker, Alice Borneman, Anthony R Curtin, Christopher D eng Germany 2018/05/11 Appl Microbiol Biotechnol. 2018 Jul; 102(14):5977-5988. doi: 10.1007/s00253-018-9054-x. Epub 2018 May 9" |
