Projects / Programmes
Genes behind aroma compounds in wine
| Code |
Science |
Field |
Subfield |
| 4.06.04 |
Biotechnical sciences |
Biotechnology |
Microbe biotechnology |
| Code |
Science |
Field |
| T490 |
Technological sciences |
Biotechnology |
| Code |
Science |
Field |
| 2.09 |
Engineering and Technology |
Industrial biotechnology |
Non-conventional yeasts, wine fermentations, spoilage, aroma-associated genes, genomics, RNAi tool, transcriptomics, metabolomics, aromatic compounds
Researchers (17)
Organisations (2)
Abstract
The compounds responsible for wine appearance, aroma, flavor and mouth-feel properties are derived from three major sources, grapes, microbes and barrel wood. The grapes provide the basic wine structure and varietal distinction. Yeasts ferment sugars from grape juice into ethanol and provide a range of sensorially important metabolites which provides the vinous character, for example esters, higher alcohols, carbonyls, fatty acids, sulfur compounds, etc. In addition to the grapes selected, one can employ a variety of processes and tools to produce wines with specific aroma and flavor profiles. The choice of yeasts for fermentation could be a very powerful tool to produce desirable sensory results, but its potential is still poorly understood and developed.
Yeasts are among the major food production microorganisms and have been used for millenia for the production of wine, beer and leaven bread. During the last decades only a few yeast species have been intensively studied in the laboratory and only a few have been used in various controlled biotech processes. A majority of yeasts, the so called non-conventional yeasts, has so far remained largely unexplored both in fundamental studies and for possible commercialisation. Yeast biodiversity constitutes a huge, untapped reservoir for potential innovation in the food sector, for example in the form of new isolates for production of new aroma compounds. In this project, we would like to study yeast genes which are responsible for specific known wine aroma as well as to explore new potential aromatic compounds, and develop/select yeast strains with different aroma profiles. We will introduce research on molecular biology, genetics, genomics, transcriptomics, metabolomics of wine related yeasts to the Vipava Valley (and the rest of Slovenia), which is becoming known for its high quality and unique styles of wines, to pioneer the new era of wine making, where complex aroma profiles could be reproducible and even pre-designed.
In food industry the increasing trend of using pure starter cultures has strongly decreased the diversity among the currently employed yeast species and even the strains within a species. We will change this trend by introducing new species and selected strains, as well as mixed cultures. We will focus on two larger yeast groups, the Saccharomyces/Kluyveromyces and Brettanomyces/Dekkera clades, which are known to be associated with the wine-making process and perform the following experiments: (i) bioinformatic analysis for the presence of genes which are already know to contribute to some aroma compunds; (ii) development of new tools to increase or decrease the expression of putative aroma genes in non-conventional yeasts; (iii) finding genes which are responsible for a certain aromatic profile and generation of mutant strains; (iv) fermentations using different yeast strains in defined medium, and afterwards transcriptome and chemical analysis; (v) must fermentations employing single yeast inoculations and co-inoculations, and subsequent analysis of the micro-flora development and aroma compounds; (vi) as the future mile stone of the project we will introduce the new strains with exciting aromatic profiles to the local wine producers.
A majority of this project will take place at UNG, however some specialized experiments and the initial training will also be performed elsewhere, for example bioinformatics and genomics in Lund (Sweden), and metabolomics in San Michele (Italy). This project will benefit directly from the »new« yeast genome sequencing programs performed in collaboration between our collaborating group in Lund and Zhenglong Gu (Cornell, US) and Ken Wolfe (Trinity College, Dublin). We also aim to develop a close relationship with the local wine producers. Apart from the new knowledge on non-conventional yeasts and aromas, our project will help to identify new isolates which could be commercialised and therefore used in food industry.
Significance for science
Baker’s yeast S. cerevisiae is the most studied eukaryote organism and has been the prime organism to develop genetic engineering tools and many genomic and post-genomic methods and approaches. These tools are now used as a platform for development of similar tools for other eukaryotic microorganisms and even mammals and humans. Most people equate yeast with S. cerevisiae, but there is an enormous diversity of other yeast species, so far more than 1500 have been identified and they represent an important group of organisms in nature. Several of these have also played important roles in traditional food processes but often in mixed cultures in spontaneous fermentations, which remain poorly understood and difficult to control. Our project increased our knowledge on yeast, and is also important to develop a platform for further studies on yeast and for development of general tools and principles to study any other living organism, especially in the field of aromatic compounds. This project was focused on less studied yeasts, providing valuable data to better understand academic aspects of biodiversity, yeast genomics, yeast genetics, yeast physiology as well as yeast evolution. Research tools were developed, like RNAi to study the relationship between a gene and its phenotype, and these will also be available for the larger world community. A significant contribution to understand the molecular background for aromas was done. New knowledge will open a large potential for generation of novel food products and for improvement of modern biotechnological processes. We gained knowledge about usage of non-conventional yeasts and possible industrial commercialization, both being very important new steps to considerably strengthen the status of the research and its applicability in this direction. The project will increase the momentum of the European Area of Wine Research and Innovation via the synergy between the public basic and applied research laboratories and private industrial partners, becoming more competitive and dynamic knowledge-based brand.
Significance for the country
The international cooperation of four research organizations was established with combining multidisciplinary knowledge of many different scientists as well as experts with practical knowledge and industry-related experiences. The partners established long-term collaborations for the exchange of specific expertise, material/equipment and know-how on the study of selected nonconventional yeast species, in particular on specific unique properties and the underlying mechanisms involved, on cultivation and analysis conditions, on tools for genetic modification and genomic and proteomic analysis, and on evaluation in fermentation trials at lab-, pilot- and industrial scale. Prof Jure Piškur’s experience and knowledge were brought back to Slovenia and shared with Slovenian scientists. He was a highly acknowledged researcher within yeast genetics and enzyme structure-function fields (with over 100 publications refeered papers, two published books, and several patents) and was experienced with establishment and management of spin-off companies and was a member of several boards of directors of biotech companies and academic institutions. Dr. Urška Vrhovšek is another very successful Slovenian researcher (with over 50 refereed papers), living and operating in Italy. U. Vrhovšek is specialized in grape, fruit and wine quality research. She currently leads the metabolomic platform at FEM which is a core technology necessary to perform competitive studies in the fields of functional genomics and nutrigenomics. It is also very appraisable that her experiences was shared and exchanged with Slovenian wine field specialists. This project offer by implementing of commonly achieved novelties to Vipava Valley and other Slovenian wine regions will offer Slovenian wine producers huge advantages, better recognition and higher competitiveness on the world wine market. Very important indirect impact of the project for the society is the development of top-level experts for this field, who will be able to transfer their knowledge to scientific and professional community through publications, who will apply new knowledge also in other industrial food branches and who will be able to include the achievements directly into the pedagogical processes.
Most important scientific results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
