magistrsko delo
Nika Rodošek (Author), Lorena Butinar (Reviewer), Neža Čadež (Mentor), Franc Čuš (Co-mentor)

Abstract

Vino je produkt alkoholne fermentacije mošta, pri kateri imajo glavno vlogo kvasovke. Začetek fermentacije je lahko spontan proces ali pa zanj uporabimo komercialne kulture. Ker imajo genetsko raznoliki sevi različen vpliv na senzorični profil vina, je pomembno, da znamo določiti njihovo prisotnost, tip in koncentracijo na grozdju, v moštu in vinu ter spremljamo njihovo dinamiko med fermentacijo. Cilj magistrskega dela je bil izbor tipizacijske metode, ki bo omogočila sledenje avtohtonim sevom vinskih kvasovk med alkoholno fermentacijo sintetičnega vina in določitev njihovega vpliva na kakovost vina. V delu smo testirali dve tipizacijski metodi, ki naj bi imeli sposobnost razlikovanja med sevi. Prva je bila analiza PCR vmesnih regij delta, s katero smo testirali zmožnost razlikovanja med komercialnimi vinskimi sevi. Vendar se je izkazalo, da metoda zaradi neponovljivosti in nezanesljivosti ni primerna. Kot drugo smo uporabili analizo mikrosatelitskih zaporedij vinskih sevov, ki je večinoma lahko razlikovala med sevi avtohtonih vinskih kvasovk (5/7). Za ovrednotenje metode smo nadalje preverili stabilnost mikrosatelitov med fermentacijo mošta. Testne fermentacije smo izpeljali v sintetičnem moštu z avtohtonimi sevi, kjer smo spremljali njihovo dinamiko, mikrobno rast in dinamiko v razmerju med sevi iz različnih vinorodnih dežel z analizo mikrosatelitov. Ob koncu združene fermentacije je bil najboljši sev iz vinorodne dežele Podravje. Z analizo mikrosatelitskih zaporedij smo želeli predvideti fenotipske lastnosti, vendar nam to ni uspelo, saj so bili genetsko najbolj sorodni sevi fenotipsko različni. Po zaključenih alkoholnih fermentacijah smo izmerili še kemijske parametre sintetičnega vina.

Keywords

vinske kvasovke;Saccharomyces cerevisiae;vino;sledenje sevom;tipizacijske metode;analiza PCR vmesnih regij delta;mikrosateliti;stabilnost;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [N. Rodošek]
UDC: 663.252.4:582.282.23:579.24/.25
COBISS: 84874243 Link will open in a new window
Views: 205
Downloads: 23
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Other data

Secondary language: English
Secondary title: Tracking of autochthonous wine yeast strains during alcoholic fermentation of synthetic must with genetic markers
Secondary abstract: Wine is a product of the alcoholic fermentation of must, in which yeasts play a major role. The start of fermentation can be a spontaneous process or we can use commercial starters. In order to understand the influence of certain strains on the sensory profile of wine, it is important to be able to determine their presence, type and concentration on grapes, synthetic must and wine and to monitor their dynamics during alcoholic fermentation. The aim of the thesis was to select a typing method that will enable the tracing of autochthonous strains of wine yeasts during wine fermentation and the determination of their impact on wine quality. In the thesis, we tested two methods for distinguishing between strains. The first was the PCR analysis of interdelta regions, with which we tested the ability to distinguish between commercial wine strains. However, this method proved to be inappropriate due to its non-repeatability and unreliability. Secondly, we used the method of analysis of microsatellite sequences of wine strains, which in most cases (5/7) was able to distinguish between strains of indigenous wine yeasts. To evaluate the method, the stability of microsatellites during fermentation was checked. Fermentation was performed in synthetic must with autochthonous strains, where we monitored its dynamics, microbial growth and dynamics in the relationship between strains from different wine growing regions by analysing microsatellites. By analysing microsatellite sequences, we wanted to predict phenotypic traits of the strains, which we were unable to do so, as it turned out that the most genetically related strains were phenotypically different. Finally, we determined the chemical composition of the synthetic wine.
Secondary keywords: wine yeasts;Saccharomyces cerevisiae;wine;strain tracking;typing methods;interdelta PCR;microsatellites;stability;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Študij mikrobiologije
Pages: X, 54 f.
ID: 13933663