Konstrukcija i određivanje osjetljivosti hibridnih sojeva kvasca Saccharomyces cerevisiae na inhibitore rasta

master's thesis

• Title (english): construction and sensitivity determination of hybrid strains of yeast Saccharomyces cerevisiae on growth inhibitors
• Author: Andrea Pranklin
• Mentor: Ivan-Krešimir Svetec (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biology and Microbial Genetics); Zagreb
• Defense date and country: 2015-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

U ovom radu korištena su dva haploidna soja kvasca Saccharomyces cerevisiae: soj YIIc17_E5 koji dobro podnosi visoke koncentracije etanola, izoliran iz vina i soj UWOPS87-2421 koji može rasti u prisutnosti nekih inhibitora rasta, a izoliran je iz cvijeta kaktusa Opuntia megacantha. Njihovim križanjem konstruirani su homozigotni i heterozigotni (hibridni) diploidni sojevi u svrhu razvoja potencijalnih producenata bioetanola iz lignoceluloznih sirovina. Rast haploidnih i konstruiranih diploidnih sojeva testiran je u prisutnosti nekoliko inhibitora koji su često prisutni u lignoceluloznim hidrolizatima (octena i levulinska kiselina te 2-furaldehid i etanol). Pokazalo se da octena i levulinska kiselina najmanje inhibiraju rast konstruiranih heterozigotnih diploidnih sojeva, a jedan od njih pokazuje i najveću toleranciju na 2-furaldehid. Također, 2-furaldehid i etanol znatno jače inhibiraju rast svih ishodnih haploidnih i konstruiranih diploidnih sojeva. Pored rezistencije na navedene inhibitore rasta, konstruirani sojevi kvasca podvrgnuti su i preliminarnom testu fermentacijske sposobnosti koja se temelji na promjeni pH podloge zbog nastajanja CO2.

Abstract (english)

In this work, two haploid Saccharomyces cerevisiae strains were used: YIIc17_E5, which tolerates high ethanol concentration, isolated from wine and UWOPS87-2421, which grows in the presence of growth inhibitors, isolated from the flower of the cactus Opuntia megacantha. Haploid strains were mated to construct homozygous and heterozygous (hybrid) diploids in order to develop potential producers of bioethanol from the raw lignocelullosic material. Growth of haploids and constructed diploids was tested in the presence of several growth inhibitors often present in lignocelullosic hydrolysate (acetic and levulinic acid, 2-furaldehydde and ethanol). It was shown that acetic and levulinic acid have the least inhibitory effect on the growth of heterozygous diploid strains and one of them shows the highest tolerance on 2-furaldehyde. Additionally, 2-furaldehyde and ethanol lead to more pronounced growth inhibition of parental haploid and constructed homozygous diploid strains. Beside resistance to the listed growth inhibitors, constructed yeast strains were subjected to preliminary fermentation test which is based on pH change of the medium due to the formation of CO2.

• Keywords: Saccharomyces cerevisiae; hibridni sojevi kvasca; inhibitori rasta; 2-furaldehid; etanol
• Keywords (english): Saccharomyces cerevisiae; hybrid yeast strains; growth inhibitors; 2-furaldehyde; ethanol
• Language: croatian
• URN:NBN: urn:nbn:hr:159:208475
• Study programme: Title: Molecular Biotechnology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka molekularne biotehnologije (magistar/magistra inženjer/inženjerka molekularne biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-03 09:37:55