20.500.12556/RUL-101524 Interakcije med vinsko in probiotično kvasovko med fermentacijo vina v membranskem fermentorju. Interactions between wine and probiotic yeast during the fermentation of wine in a membrane fermenter Vino je kompleksen pridelek interakcij med kvasovkami in bakterijami, ki tekom fermentacije grozdnega soka vplivajo na nastanek ključnih sestavin. Med celicami kvasovk delujejo različni mehanizmi medsebojnih odnosov, ki omogočajo preživetje ter hitrejšo rast. V našem delu smo za študij medsebojnih odnosov med različnimi sevi kvasovk izbrali dva seva, ki imata različno genetsko ozadje in sicer vinski sev Saccharomyces cerevisiae in probiotični sev S. boulardii (nom.nud.). Fermentacijo sintetičnega mošta smo izvedli v dvoprekatnem membranskem fermentorju, v katerem smo celice različnih/istih sevov ločili z membranskim filtrom. Dinamiko fermentacije smo spremljali na podlagi kinetike rasti obeh sevov in preko porabe glukoze in fruktoze ter tvorbe produktov fermentacije, kot sta etanol in glicerol. Spremljali smo tudi koncentracije organskih kislin (ocetna, citronska, vinska in jabolčna kislina). Ugotovili smo razlike v dinamiki fermentacije med vinsko in probiotično kvasovko, vendar se ta dinamika ni spremenila pri združenih kulturah. Koncentracije hlapnih spojin, ki smo jih določili s plinsko kromatografijo, kot sta acetaldehid in ocetna kislina, so nakazale kompetitiven odziv med sevoma združene fermentacije. Zaznavanje prisotnosti drugega seva kvasovke smo določali preko sinteze signalnih molekul 2-feniletanola, tirozola in triptofola ter določili izražanje genov, odgovornih za medcelično komunikacijo v različnih stopnjah fermentacije. Ugotovili smo, da največjo koncentracijo signalnih molekul proizvaja vinska kvasovka v posamični kulturi, v združeni kulturi pa je sinteza molekul regulirana s prisotnostjo drugega seva. Prav tako je bilo izražanje (ARO, PAU17, THI12) genov povečano v prisotnosti drugega seva. Wine is a complex product of interactions between yeasts and bacteria, which during the fermentation of grape juice affect the formation of key components. There are various mechanisms of interections between the yeast cells that enable survival as well as faster growth. In order to study interactions between different strains of yeasts we have selected two strains that have a different genetic background, namely the Saccharomyces cerevisiae wine strain and the probiotic strain S. boulardii (nom.nud.). The fermentation of the synthetic must was carried out in a double-stranded membrane fermentor in which cells of different/same strains were separated by the membrane filter. The fermentation dynamics was monitored on the basis of the growth kinetics of the two yeast strains and the consumption of glucose and fructose, and the formation of fermentation products such as ethanol, glycerol. We also monitored the concentrations of organic acids (acetic, citric, tartaric and malic acid). We detected variations in the fermentation dynamics between wine and probiotic yeast, however the dynamics did not change in the combined cultures. The concentrations of the volatile compounds were determined using gas chromatography, such as acetaldehyde and acetic acid, indicated a competitive response between the coupled fermentation strains. The detection of the presence of another yeast strain was determined by the synthesis of signal molecules of 2-phenylethanol, thyrosol, and tryptophol and determined by the expression of the genes responsible for intracellular communication at different stages of fermentation. We have found that the maximum concentration of signal molecules produces wine yeast in a particular culture, while in unified cultures the synthesis of the molecule is regulated by the presence of the second strain. Similarly, expression (ARO, PAU17, THI12) of genes was increased in the presence of another strain. alkoholna fermentacija vinska kvasovka probiotična kvasovka Saccharomyces cerevisiae Lalvin EC-1118 (Lallemand) Saccharomyces boulardii (nom.nud.) interakcije med kvasovkami signalne molekule aromatični profil alcohol fermentation wine yeasts probiotic yeasts Saccharomyces cerevisiae Lalvin EC-1118 (Lallemand) Saccharomyces boulardii (nom.nud.) interactions between yeasts signaling molecules aromatic profile true false false [T. Močnik] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2018-06-14 07:45:06 2018-06-14 07:45:13 2022-08-14 03:44:57 0000-00-00 00:00:00 2018 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 602.3.:582.282.23:663.252.3(043.2) 151314 8993145 3076.pdf 3076.pdf 1 C9FE48B5973DC32792BC7C099CC0BAE8 5f05c3c05cef7627b6f613f3f3caeaaa662647d6de87d38b5b00083e15b091bc 4c4952af-a1b5-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=111595 Biotehniška fakulteta 0 0 0