Biotechnology-2013: Yeast metabolic engineering or biodiversity: Understanding “flavor phenotypes” in traditional fermented beverages - Francisco Carrau - Universidad de la Republica


Abstract Development of yeast strains that enhance or increase flavors and sensory complexity of fermented beverages is a challenge. It has been well stated that formation of the most dominant aroma compounds in fermented beverages depend more on yeasts than in the raw material used for fermentation. Application of the same yeast commercial strains in different regions of the world results in uniform products and limits flavor diversity. As sterile conditions are not recommended for the winemaking process, grape and wine microbiology research have contributed substantially to understand how yeast biodiversity could affect the inoculated commercial yeast or how to conduct a spontaneous fermentation. Traditionally, industrial phenotypes searched for in yeast selection are the ability to complete fermentation, higher fermentation rate or the ability to degrade maltose in brewing strains. The “flavor phenotype” is a more complicated concept considering that more than 1300 volatile compounds have been detected in wine. The principal yeast used in today’s food and alcoholic beverage industries for the production of bread, beer, spirits, cider and wine is classified as Saccharomyces cerevisiae. However, this model eukaryote represents less than 1 percent of the yeast flora that participates in the grape and wine biotechnology process. Application of non-Saccharomyces yeasts and mixed cultures with Saccharomyces to increase flavor complexity in fermented beverages will offer ground-breaking opportunities to the food industry. Microbial biodiversity and metabolic engineering strategies are compared as tools to achieve direct impact on the consumer sensory expectations.  clinical understanding grows at an exponential charge, and nowhere is this extra evident than within the historical milestones of chemistry and biology which have formed our understanding of the biology of the microorganisms that drive fermentation. This progress has been decorated with some of the most extensive names within the chemical and organic sciences, including van Leeuwenhoek, Lavoisier, homosexual-Lussac, Pasteur, Buchner and Koch. One might argue that the maximum crucial check tube within the delivery and boom of the contemporary lifestyles sciences is the fermenter, and the most essential version organism has been the yeast Saccharomyces cerevisiae usually called baking, brewing or wine yeast. As readers may recognize, that is exemplified within the foundation of the phrase enzyme— ‘en' which means within and ‘zyme' which means leaven. Yeast has been crucial to pioneering paintings in microbiology and biochemistry, in particular in the fields of metabolism and enzymology.  At some point of the early a long time of the twentienth century the location for S. cerevisiae in essential research turned into affirmed, and there are several desirable motives for this. Our near dating with this yeast in food and beverage manufacturing over millennia tells us that it's miles safe to paintings with; as showed by using its ‘commonly recognised as safe' designation by using the usa food and Drug administration. similarly, it's far inexpensive, easy to grow and can be saved for lengthy durations in suspended animation. possibly the maximum critical element is that it has handy genetics that can be followed thru sexual and asexual cycles (Barnett, 2007). The 1970s set the degree for some other explosion of knowledge, sparked by the arrival of gene generation and pushed by a convergence of genetics, biochemistry, mobile biology, microbiology, physical and analytical chemistry, as well as computing brought collectively underneath the banner of molecular biology . Yeast molecular biology was established when Gerald Fink's group in the u.s. confirmed that yeast may be converted with foreign DNA (Hinnen et al, 1978). inside the identical yr, Jean Beggs inside the uk developed a shuttle vector among Escherichia coli and S. cerevisiae that enabled cloning in yeast (Beggs, 1978). Winemaking, science and era have interwoven histories and feature grown together over the millennia, taking advantage of every other. although technology is an important a part of an oenologist's schooling and scientific techniques and device are mechanically hired within the vineyard, winemakers aren't scientists in line with se. there, possibly more as it should be regarded as artisans, with the emphasis at the ‘artwork'. As for many human endeavours, the humanities progress with trends in era; think about the usage of acrylic paint in the great arts given that its introduction within the 1950s, or David Hockney's use of a Polaroid digital camera to create photocollages. inside the way that acrylic paint and pictures have furnished extra options to artists, permitting them to develop their horizons, yeast science and technology is including to the winemaker's palette. Who knows what bottled masterpieces look forward to us as we sculpt novel yeast lines within the laboratory the use of molecular, structures and artificial biology The most effective real impediment that we are facing is patron popularity of GMOs; we can handiest wish that rationality will in the end be triumphant.  The results of this paintings were promising, however, once they have been carried over to wine yeast, the findings were as a substitute special. There have been even large variations between wine yeast lines, leading the authors to warning that “optimisation of the flocculation pattern of individual commercial traces will need to be based on a stress-by-strain approach” (Govender et al, 2010). nonetheless, managed expression of FLO genes at the cease of fermentation stays a plausible technique for improving the overall performance of wine yeast, however the strategies required to acquire a proper outcome might be extra complicated than became at the start idea. whilst the complexity of biological structures is a purpose for excitement and wonder to maximum biologists, it may make engineering novel lines for industrial applications trickier than molecular biology and biotechnology textbooks would possibly propose. For those folks running on commercial yeast lines, it might be pertinent to without delay tackle the problem of complexity and use structures biology procedures to higher apprehend the workings of yeast metabolism. This must lead to greater correct modelling of metabolic procedures for higher-knowledgeable manipulations, to reap targeted, predictable effects.    Biography   Francisco Carrau is Professor Head of the Enology Section of the Food Science Department of University of the Republic and Head Winemaker of his family owned Winery in Uruguay. He was graduated in Biological Sciences at the University of the Republic Uruguay, Faculty of Sciences, in 1987. In 2003 he obtained his Ph.D. in Chemistry in the same University at the School of Chemistry and at the Australian Wine Research Institute (Dr. Paul A. Henschke). Since April 2011 is leading the Enology and Fermentation Biotechnology Group of the CSIC I+D programme of University of the Republic, UdelaR, Uruguay (2011-2014).  [email protected]

Relevant Publications in Research & Reviews: Journal of Pharmaceutics and Nanotechnology