Vloga kvasovke vrste Kregervanrija fluxuum pri fermentaciji jabolčnega vina

Jovanova, Viktorija (author), Čadež, Neža (mentor), Košmerl, Tatjana (comentor)

Namen magistrske naloge je bil ohranitev genetskega potenciala za sestavo združene starterske kulture jabolčnega vina in določitev vpliva ne-Saccharomyces kvasovke Kregervanrija fluxuum na fizikalno-kemijske in senzorične lastnosti jabolčnega vina z mikro-fermentacijami v sterilnem jabolčnem soku. V mikrobiološkem delu naloge smo na selektivnih trdnih gojiščih revitalizirali kvasovke in bakterije, izolirane iz enajstih spontanih fermentacij vina iz Koroške regije. Z metodo PCR smo pomnožili variabilni del ribosomskega gena kvasovk in bakterij, kateremu so nato določili nukleotidno zaporedje. Na podlagi le-tega smo potrdili ali določili identiteto 71 sevom kvasovk in 18 sevom bakterij ter jih trajno shranili v Zbirki industrijskih mikroorganizmov, s čimer smo prispevali k ohranitvi mikroorganizmov tradicionalnega proizvoda Koroške regije. Drugi del naloge je zajemal mikrofermentacije jabolčnega soka s posamičnimi in združenimi kulturami Kregervanrija fluxuum, Saccharomyces uvarum, Dekkera bruxellensis in Oenococcus oeni, ter spremljanje kinetike fermentacij s spremljanjem rasti posameznih kultur in z gravimetrično metodo z namenom določitve vloge K. fluxuum pri fermentaciji. K. fluxuum je že po 24 urah fermentacije dosegla stacionarno fazo, v primeru posamične kulture je njeno število rahlo naraščalo med celotno fermentacijo jabolčnega soka.V združeni starterski kulturi se je takoj po doseženi stacionarni fazi število celic začelo zmanjševati ter na koncu fermentacije ni bila detektirana, le v odsotnosti D. bruxellensis je bila prisotna med celotno fermentacijo. Po končani fermentaciji smo z analizo WineScan pridobili rezultate o fizikalno-kemijskih parametrih vina, ter naredili senzorično analizo. Med fermentacijo jabolčnega vina K. fluxuum ni tvorila alkohola, vendar pa je prispevala k večji tvorbi glicerola.

• Language: Slovenian
• Keywords: jabolčno vino, cider, ne-Saccharomyces kvasovke, Kregervanrija fluxuum, kinetika fermentacij, mikrofermentacija, starterske kulture
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [V. Jovanova]
• Year: 2018
• PID: 20.500.12556/RUL-105415
• UDC: 663.31:582.282.23:543.2/.9
• COBISS.SI-ID: 5003128
• Publication date in RUL: 28.11.2018

JOVANOVA, Viktorija, 2018, Vloga kvasovke vrste Kregervanrija fluxuum pri fermentaciji jabolčnega vina [online]. Master’s thesis. V. Jovanova. [Accessed 13 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=105415

Secondary language

• Language: English
• Title: The role of yeast species Kregervanrija fluxuum in cider fermentations

Abstract

The purpose of the master's thesis was to preserve the genetic potential for mixed starter culture of apple wine and to determine the effect of the non-Saccharomyces yeast Kregervanrija fluxuum on the physico-chemical and sensory properties of apple wine by micro-fermentations in sterile apple juice. In the microbiological part of the study, yeast and bacteria from eleven spontaneous fermentations of wines from the Koroška region were revitalized in selective solid media. Using the PCR method, we amplified and sequenced the variable part of the ribosomal gene of yeasts and bacteria. Altogether, 71 strains of yeasts and 18 strains of bacteria autochthonous to Koroška region were preserved in the Collection of Industrial Microorganisms. In the second part of the study we followed apple juice microfermentation of mono- and co-cultures of Kregervanrija fluxuum, Saccharomyces uvarum, Dekkera bruxellensis and Oenococcus oeni by detemining cell concentrations of each culture and by the gravimetric method. K. fluxuum reached the stationary phase after 24 hours of fermentation. In the case of a pure culture, its number increased slightly during the entire fermentation of apple juice. In mixed starter culture, immediately after the stationary phase was reached, the number of cells began to decrease and at the end of the fermentation was not detected only in the absence of D. bruxellensis was present throughout the fermentation. Therefore, after completion of the fermentation, physico-chemical parameters of ciders were determined by WineScan and a sensory analysis was conducted. The results showed that during the fermentation of ciders K. fluxuum did not form alcohol, but it contributed to a greater formation of glycerol.

• Keywords: apple wine, cider, non-Saccharomyces yeasts, Kregervanrija fluxuum, fermentation kinetics, microfermentation, starter cultures