20.500.12556/RUL-121238 Genetska stabilnost izbranega seva kvasovke za proizvodnjo ajdovega in prosenega piva v zaporednih fermentcijah Genetic stability of selected yeast strain for repitching of buckwheat and millet beer production Proces proizvodnje piva v industrijskem merilu se z namenom znižanja proizvodnjih stroškov poslužuje ponovne uporabe izbrane starterske kulture kvasovk, s čimer prihaja do kopičenja genetskih sprememb v celicah. Namen magistrskega dela je bila analiza genetske stabilnosti izbranega seva kvasovk izoliranega iz jabolčnega vina na Koroškem Saccharomyces cerevisiae ZIM 3704, ki smo ga uporablili v 30-ih zaporednih enotedenskih fermentacijah ječmenove, ajdove in prosene pivine v konusnih minifermentorjih pri 14 °C. V tem času smo vsak teden preverili stopnjo živosti celic s kultivacijo na trdnem gojišču in z metodo barvanja z metilenskim modrilom, preverili smo stopnjo flokulacije. Rezultati živosti celic so bili odvisni od tipa pivine (ajdove, ječmenove, prosene), vendar so ostali tudi po 30. zaporedni uporabi okoli 95 %. Z analizo flokulacije smo ugotovili, da izbrani sev najbolje flokulira v ječmenovi pivini in najslabše v proseni. Z analizo HPLC smo določili sposobnost seva izrabe sladkorjev različnih pivin in produkcije primarnih metabolitov. Pokazali smo, da je sposobnost izrabe maltoze pri 30. zaporedni uporabi višja od začetne fermentacije. Delež izrabe maltotrioze v ječmenovi pivini je naraščal s sposobnostjo izrabe maltoze. Koncentraciji glicerola in etanola sta bili povezani obratnosorazmerno, saj se ob povišanju koncentracije glicerola, koncentracija etanola zniža. V nadaljevanju smo določili tudi genetsko stabilnost različnih morfotipov po 30-ih zaporednih uporabah seva v mikrosatelitnih zaporedij DNA in določili dolžinske spremembe kromosomov z elektroforezo v pulzirajočem polju. Obe metodi nista pokazali genetskih sprememb, zato smo le-te dokazali s tehnologijo naslednje generacije sekvenciranja, saj smo dokazali prisotnost dodatnih retrotranspozonov in nekodirajočih regij med eksoni. In the industrial beer production yeast repitching is often used to decrease economic cost of production, this can lead to genetic modifications in the yeast cells. The aim of the master thesis was to characterize the genetic stability of chosen strain isolated from Carinthian cider Saccharomyces cerevisiae ZIM 3704, during 30 series of one-week fermentations of barley, buckwheat and millet wort in conical minifermentors at 14 °C. During each week we determinated cell viability with cultivation on a solid medium and method of methylene blue staining, we also determinated flocculation rate. Cell viability results were dependent upon among different types of worth (buckweat, barley and millet), but after 30 uses they are still around 95%. Flocculation analysis showed that the strain used for fermentation of barley wort had the highest flocculation, while the strain used for fermentation of millet wort had lowest. With HPLC analysis we determinated strain capability of sugar uptake in different worths and primary metabolite production. We showed that maltose uptake is higher at 30th fermentation then at the first one. The consumed maltotriose increased with increasing consumption of maltose. Concentration of ethanol and glycerol were inversely proportional connected, because when the concentration of glycerol gets higher, the concentration of ethanol falls. In addition, it was also determinated genetic stability between different yeast morpotypes after 30. repitches in DNA microsatellite region and lenght changes in chromosome with pulse-field electrophoresis. Both methodes showed no changes, so we proved them with next generation sequencing, which showed presence of new retrotransposones and noncoding regions among exons kvasovke Saccharomyces cerevisiae pivo ajda proso ječmen zaporedna uporaba biomase genetska stabilnost mikrosateliti genom PFGE Ilumina yeasts Saccharomyces cerevisiae beer buckwheat millet barley repitching genetic stability microsatellites genome PFGE Ilumina true false false [M. Podgoršek] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2020-10-02 07:16:56 2020-10-02 07:17:00 2022-09-01 04:02:15 0000-00-00 00:00:00 2020 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 606:663.476:602.3:582.282.23(043.2) 183460 32303363 11301.pdf 11301.pdf 1 705F4589EC9A9A99A9CF523AB10CA9D2 3a3358960d34d774087cd44f9e428ec9bc309574dbf8930aaef0164d6c3111af 44efc296-a1ba-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=136144 Biotehniška fakulteta 0 0 0