diploma thesis
Natalia Mikhaylina (Author), Lorena Butinar (Mentor)

Abstract

The aim of this study was to explore the diversity of fermentative yeast species in a non-vineyard and vineyard environment, and exploit their oenological potential. For this purpose we collected plant and soil material in the vineyard (located in Črniče in Vipava Valley) planted with Vitis vinifera L. and in the forest (forest in Vipava Old Castle), and by using a selective medium with high ethanol and sugar content we managed to obtain 35 isolates. By sequencing the D1/D2 domain of the 26S rDNA we identified nine different yeast species. The oenological potential of identified yeasts was further investigated by employing a series of tests, such as growth at low pH values, tolerance to ethanol and sulfur, and H2S production ability. Based on the results of these tests we selected four different yeast species for the microvinification of Vitis vinifera L. cv. ‘Pinot Noir’ grape juice. A commercial strain Saccharomyces cerevisiae Lalvin D47 was also included as a control in the fermentation experiment. Fermentation monitoring was done by measuring daily weight loss and microbiological analysis in the middle of fermentation. For the final wines, sugars were determined and sensorial evaluation performed. Among four tested yeasts, S. paradoxus IVV 32 and Torulaspora delbrueckii IVV 36 appeared to be the most promising for winemaking, but further studies should be carried out.

Keywords

wine;Vitis vinifera L. cv. ‘Pinot Noir’;biodiversity;yeasts;fermentation;

Data

Language: English
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UNG VŠVV - College of Viticulture and Enology
Publisher: [N. Mikhaylina]
UDC: 634.8+663.2
COBISS: 4839931 Link will open in a new window
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Downloads: 274
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Other data

Secondary language: Slovenian
Secondary title: Izolacija in selekcija divjih kvasovk za vinarstvo
Secondary abstract: Namen študije je bil preučiti pestrost fermentativnih kvasovk v ne-vinogradniškem in vinogradniškem okolju ter raziskati njihov enološki potencial. V ta namen smo vzorčili različen rastlinski in talni material v vinogradu (nahajajočem se v Črničah v Vipavski dolini) in gozdu (Stari grad nad Vipavo), iz katerega smo s pomočjo uporabe selektivnega gojišča z visoko vsebnostjo sladkorja in etanola uspeli izolirati 35 izolatov. S sekvenciranjem domene D1/D2 na 26S rDNA smo določili devet različnih vrst kvasovk. Z izvedbo serije testov, kot je rast pri nizkih vrednostih pH-ja, tolerance na etanol in žveplo ter sposobnosti tvorbe H2S, smo nadalje raziskali enološki potencial določenih kvasovk. Na podlagi rezultatov teh testov smo za izvedbo mikrovinifikacije grozdnega soka sorte Vitis vinifera L. cv. ‘Modri pinot’ izbrali štiri različne vrste kvasovk, kot kontrolo smo vključili tudi komercialni sev Lalvin D47 vrste Saccharomyces cerevisiae. S spremljanjem dnevne izgube teže in mikrobiološko analizo sredi fermentacije smo izvedli monitoring fermentacije. Končnim vinom pa smo določili vsebnost sladkorjev in izvedli senzorično oceno. Med štirimi testiranimi kvasovkami, sta se seva IVV 32 vrste S. paradoxus in IVV 36 vrste Torulaspora delbrueckii pokazala kot najbolj obetajoča za proizvodnjo vina, vendar pa so potrebne nadaljnje raziskave.
Secondary keywords: diplomske naloge;vino;Vitis vinifera L.;modri pinot;biotska raznovrstnost;kvasovke;fermentacija;
URN: URN:SI:UNG
Type (COBISS): Bachelor thesis/paper
Thesis comment: Univ. v Novi Gorici, Visoka šola za vinogradništvo in vinarstvo
Pages: XII, 43 str.
ID: 10847425