magistrsko delo
Karin Bokal (Author), Neža Čadež (Mentor), Neža Čadež (Thesis defence commission member), Hrvoje Petković (Thesis defence commission member), Mojca Narat (Thesis defence commission member), Tomaž Accetto (Thesis defence commission member), Hrvoje Petković (Co-mentor)

Abstract

Nekonvencionalne kvasovke imajo zaradi fenotipske raznolikosti velik potencial za uporabo v biotehnologiji, predvsem če lahko rastejo na lignoceluloznem substratu, ki predstavlja ekonomsko in okoljevarstveno zanimivo rešitev za proizvodnjo kemikalij. V raziskovalnem delu smo izbrali 68 genetsko raznolikih sevov rodu Dekkera, ki smo jih tipizirali z metodo RAPD-PCR. Za presejalne teste sposobnosti rasti na različnih komponentah lignoceluloznega substrata smo dodali 12 sevov kvasovk izoliranih iz rastlinskih virov ter 2 tipska seva. Drugi presejalni test je zajemal testiranje rasti sevov na različnih tipih lignoceluloznih hidrolizatov, in sicer 28 sevov, izbranih na podlagi vrednotenja stopnje rasti, katerim smo dodali 28 novih sevov. Seve smo razvrstili v skupine glede na relativno stopnjo rasti. Sedmim sevov smo po aerobni kultivaciji ugotovili specifično hitrost rasti in odstotek izrabe ogljikovih hidratov v lignoceluloznem mediju. Specifično hitrost rasti smo ugotovili s štetjem plošč na začetku in na koncu kultivacije. Koncentracijo sladkorjev smo ugotovili s tekočinsko kromatografijo visoke ločjivosti. Najbolj primerni sevi za izrabo lignoceluloznega hidrolizata so bili sevi Schwanniomyces polymorphus ZIM 2980, ki je izrabil 97,0 % sladkorjev v mediju, Pichia kudriavzevii ZIM 3106, ki je izrabil 82,4 % sladkorjev v mediju in Saccharomyce cerevisiae ZIM 3418, ki je izrabil 83,1 % sladkorjev v mediju. Ugotovili smo, da lahko le nekateri sevi/vrste nekonvencionalnih kvasovk izrabljajo lignocelulozni hidrolizat, kar kaže na relativno veliko raznolikost, ki jo lahko povežemo z naravnim habitatom teh sevov.

Keywords

lignoceluloza;lignocelulozni hidrolizat;nekonvencionalne kvasovke;Dekkera bruxellensis;Saccharomyces cerevisiae;Schwannyomyces polymorphus;Pichia kudriavzevii;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [K. Bokal]
UDC: 602.3:582.282.23:579.66(043.2)
COBISS: 9053049 Link will open in a new window
Views: 779
Downloads: 303
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Other data

Secondary language: English
Secondary title: Efficient utilization of lignocellulosic substrat of nonconvencional yeast
Secondary abstract: Non-conventional yeast have great potential for use in biotechnology because of their phenotypic diversity, especially if they are able to grow on a lignocellulosic substrat, which is economically and environmentally interesting solution for production of chemicals. In our research, we selected 68 genetically diverse strains of genus Dekkera, which were typed using RAPD-PCR method and tested for their ability to grow on components of lignocellulosic hydrolysate. For screening test 12 yeast strains isolated from plant sources and 2 typical strains were added. Second screening test included testing of strain growth on various types of lignocellulosic hydrolysates. We chose 28 strains based on growth rate assessment, to which we added 28 new strains. Strains were grouped according to their relative growth rate. Seven strains were aerobically cultivated for which specific growth rate and percentage of carbohydrate consumtion in hydrolysate medium were evaluated. Specific growth rate was deterimed by plating at the beginning and at the end of cultivation, sugar concentrations were mesasured by high performance liquid chromatography in spent media. The most suitable strains for the efficient use of lignocellulosic hydrolysate were Schwanniomyces polymorphus ZIM 2980, which utilized 97,0% of sugars in medium, Pichia kudriavzevii ZIM 3106, which utilized 82,4% of sugars in medium and Saccharomyce cerevisiae ZIM 3418, which utilized 83,1% of sugars in medium. We found out that only some strains/species of non-conventional yeast are able to use lignocellulosic hydrolysate, which indicates a relatively large variety of yeast that can be linked to source of yeast's isolation.
Secondary keywords: lignocellulose;lignocellulosic hydrolysate;nonconvencional yeasts;bioethanol;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Študij biotehnologije
Pages: XI, 63 f., [4] f. pril.
ID: 10962419