Ispitivanje utjecaja izvora ugljika i dušika na proizvodnju lignocelulolitičkih enzima s pomoću kvasca Debaryomyces hansenii

master's thesis

• Title (english): Analysis of the effect of carbon and nitrogen sources on the production of lignocellulolytic enzymes by yeast Debaryomyces hansenii
• Author: Katja Blažević
• Mentor: Božidar Šantek (mentor)
• Mentor: Nenad Marđetko (pomoć pri izradi, neposredni voditelj)
• Committee member: Antonija Trontel (predsjednik povjerenstva)
• Committee member: Andreja Leboš-Pavunc (član povjerenstva)
• Committee member: Jasna Novak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2025-01-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Lignocelulozne sirovine predstavljaju značajan izvor obnovljivih resursa koji se koriste u različitim industrijama. Njihova razgradnja uz pomoć lignocelulolitičkih enzima ključna je za biotehnološke procese, jer omogućava efikasnu proizvodnju korisnih proizvoda poput biogoriva i biokemikalija. Dodatno, ti enzimi imaju primjenu u brojnim industrijama čime dodatno povećavaju svoj značaj u održivom razvoju. U ovom istraživanju, na temelju preliminarnih analiza identificiran je kvasac D. hansenii kao dobar proizvođač karboksimetil celulaze (CMC-aze). Zatim je optimiziran sastav hranjive podloge za uzgoj D. hansenii, kroz varijacije u izvorima ugljika i dušika, s ciljem povećanja aktivnosti lignocelulolitičkih enzima. Kvaščev ekstrakt, u omjeru izvora ugljika i dušika 2:1, pokazao se optimalnim za poticanje lignocelulolitičke aktivnosti. Osim toga, lignocelulozna biomasa (čvrsti hidrolizat biljke blještac) se pokazala kao dobar induktor enzimske aktivnosti. Kod uzgoja D. hansenii u bioreaktoru uz melasu i kvaščev ekstrakt postignute su ove specifične enzimske aktivnosti (U guk. proteina⁻¹): 772 za celulazu, 1700 za CMC-azu i 156 za ksilanazu, što potvrđuje potencijal D. hansenii u razgradnji lignoceluloznih sirovina.

Abstract (english)

Lignocellulosic raw materials represent a significant renewable resource used in various industries. Their degradation with the help of lignocellulolytic enzymes is crucial for biotechnological processes, as it enables the efficient production of valuable products such as biofuels and biochemicals. Additionally, these enzymes find applications in numerous industries, further enhancing their importance in sustainable development. In this study, based on preliminary analyses, the yeast D. hansenii was identified as a good producer of carboxymethyl cellulase (CMC-ase). Subsequently, the nutrient medium for cultivating D. hansenii was optimized through variations in carbon and nitrogen sources to increase lignocellulase activity. A yeast extract with a carbon-to-nitrogen ratio of 2:1 proved to be optimal for promoting lignocellulolytic activity. Furthermore, lignocellulosic biomass (solid part of reed canary grass hydrolysate) was shown to be an effective inducer of enzymatic activity. The cultivation of D. hansenii in a bioreactor using molasses and yeast extract was also conducted. The specific enzyme activities achieved in bioreactor (U guk. proteina⁻¹) were: 772 for cellulase, 1700 for CMC-ase, and 156 for xylanase, confirming the potential of D. hansenii in the degradation of lignocellulosic materials.

• Keywords: lignocelulolitički enzimi; optimizacija; izvor ugljika i dušika; kvasac Debaryomyces hansenii
• Keywords (english): lignocellulolytic enzymes; optimization; carbon and nitrogen source; yeast Debaryomyces hansenii
• Language: croatian
• URN:NBN: urn:nbn:hr:159:009523
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-01-09 12:38:22