المؤلفون: Javier Vicente, Eva Navascués, Fernando Calderón, Antonio Santos, Domingo Marquina, Santiago Benito

المصدر: Foods; Volume 10; Issue 11; Pages: 2878

مصطلحات موضوعية: Lachancea thermotolerans, lactic acid, wine, acidity, volatile, evolution, transcriptomic, metabolism regulation, lactate dehydrogenase enzymes

جغرافية الموضوع: agris

الوصف: The interest in Lachancea thermotolerans, a yeast species with unusual characteristics, has notably increased in all ecological, evolutionary, and industrial aspects. One of the key characteristics of L. thermotolerans is the production of high quantities of lactic acid compared to other yeast species. Its evolution has mainly been driven by the influence of the environment and domestication, allowing several metabolic traits to arise. The molecular regulation of the fermentative process in L. thermotolerans shows interesting routes that play a complementary or protective role against fermentative stresses. One route that is activated under this condition is involved in the production of lactic acid, presenting a complete system for its production, showing the involvement of several enzymes and transporters. In winemaking, the use of L. thermotolerans is nowadays mostly focused in early–medium-maturity grape varieties, in which over-ripening can produce wines lacking acidity and with high concentrations of ethanol. Recent studies have reported new positive influences on quality apart from lactic acid acidification, such as improvements in color, glutathione production, aroma, malic acid, polysaccharides, or specific enzymatic activities that constitute interesting new criteria for selecting better strains. This positive influence on winemaking has increased the availability of commercial strains during recent years, allowing comparisons among some of those products. Initially, the management of L. thermotolerans was thought to be combined with Saccaharomyces cerevisiae to properly end alcoholic fermentation, but new studies are innovating and reporting combinations with other key enological microorganisms such as Schizosaccharomyces pombe, Oenocous oeni, Lactiplantibacillus plantarum, or other non-Saccharomyces.

وصف الملف: application/pdf

العلاقة: Food Quality and Safety; https://dx.doi.org/10.3390/foods10112878Test

الإتاحة: https://doi.org/10.3390/foods10112878Test

المؤلفون: Georgios Sgouros, Athanasios Mallouchos, Maria-Evangelia Filippousi, Georgios Banilas, Aspasia Nisiotou

المصدر: Foods; Volume 9; Issue 5; Pages: 595

مصطلحات موضوعية: biological acidification, wine fermentation, yeast starter cultures, Lachancea thermotolerans, wine chemical profile, volatiles, transcriptional analysis, lactic acid, lactate dehydrogenase, alcohol dehydrogenase

جغرافية الموضوع: agris

الوصف: Lactic acid production is an important feature of the yeast Lachancea thermotolerans that has gained increasing interest in winemaking. In particular, in light of climate change, the biological acidification and ethanol reduction by the use of selected yeast strains may counteract the effect of global warming in wines. Here, the enological potential of a high lactate-producing L. thermotolerans strain (P-HO1) in mixed fermentations with S. cerevisiae was examined. Among the different inoculation schemes evaluated, the most successful implantation of L. thermotolerans was accomplished by sequential inoculation of S. cerevisiae, i.e., at 1% vol. ethanol. P-HO1produced the highest levels of lactic acid ever recorded in mixed fermentations (10.4 g/L), increasing thereby the acidity and reducing ethanol by 1.6% vol. L. thermotolerans was also associated with increases in ethyl isobutyrate (strawberry aroma), free SO2, organoleptically perceived citric nuances and aftertaste. To start uncovering the molecular mechanisms of lactate biosynthesis in L. thermotolerans, the relative expressions of the three lactate dehydrogenase (LDH) paralogous genes, which encode the key enzyme for lactate biosynthesis, along with the alcohol dehydrogenase paralogs (ADHs) were determined. Present results point to the possible implication of LDH2, but not of other LDH or ADH genes, in the high production of lactic acid in certain strains at the expense of ethanol. Taken together, the important enological features of P-HO1 highlighted here, and potentially of other L. thermotolerans strains, indicate its great importance in modern winemaking, particularly in the light of the upcoming climate change and its consequences in the grape/wine system.

وصف الملف: application/pdf

العلاقة: Food Microbiology; https://dx.doi.org/10.3390/foods9050595Test

الإتاحة: https://doi.org/10.3390/foods9050595Test