Přístupnostní navigace
E-application
Search Search Close
Bachelor's Thesis
Author of thesis: Dominik Hübsch
Acad. year: 2025/2026
Supervisor: Ing. Jiří Holub, Ph.D.
Reviewer: Ing. Jan Obračaj
This bachelor thesis investigates the potential biotechnological use of selected food-industry waste substrates for yeast cultivation. Cheese whey and a hydrolysate prepared from spent coffee grounds were used as model substrates. Their effects on the growth of the yeast strains Rhodotorula toruloides, Metschnikowia pulcherrima and Cystofilobasidium infirmominiatum were evaluated together with biomass production, extracellular polymeric substances, beta-glucan content and selected lipid compounds determined by HPLC analysis. The effects of different proportions of the waste substrates and adjustment of the carbon-to- nitrogen ratio to C/N 13 were also assessed. The results showed that both substrates could be utilised for yeast cultivation, although their effects depended on the particular strain and cultivation conditions. Cheese whey was generally more suitable for stable cell growth and biomass production, with favourable results often observed when it partially replaced the mineral medium. The spent coffee grounds hydrolysate created more demanding cultivation conditions; however, under selected conditions, it promoted the production of extracellular polymeric substances. Beta-glucan production and the profile of compounds determined by HPLC analysis were strongly strain- specific. The strain R. toruloides showed the most pronounced production of carotenoid pigments, whereas ubiquinone or ergosterol were more prominent in the other strains. The obtained results confirm that cheese whey and spent coffee grounds can serve as accessible secondary raw materials for the production of microbial biomass and value-added compounds. However, the optimal cultivation conditions depend on the target product and the yeast strain used.
food-industry waste, cheese whey, spent coffee grounds, yeasts, biomass, extracellular polymeric substances, beta-glucan, bioactive compounds
Date of defence
16.06.2026
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
1. Student seznámil členy komise s náplní a cílem bakalářské práce. 2. Byly přečteny posudky na bakalářskou práci. 3. Student akceptoval všechny připomínky oponenta a na všechny otázky odpověděl v plné šíři. Diskuse: prof. RNDr. Ivana Márová, CSc. Jaký objem měly jamky používané pro kultivace na mikrotitračních destičkách? doc. Ing. Pavel Diviš, Ph.D. Co vyjadřují 2 g/l fenolických látek? prof. Ing. Stanislav Obruča, Ph.D. Jakým způsobem byly měřeny exopolysacharidy? Testovali jste na obsah polysacharidů i samostatný substrát? Upravovali jste syrovátkový substrát? Odstraňovali jste z něj proteiny? Student odpověděl na doplňující otázky členů komise, které byly v průběhu diskuse k dané problematice vzneseny. Student prokázal dobré odborné znalosti, ale i schopnost samostatné prezentace dosažených výsledků.
Language of thesis
Slovak
Faculty
Fakulta chemická
Department
Institute of Food Science and Biotechnology
Study programme
Chemistry and Technology of Foodstuffs (BPCP_CHTPO)
Specialization
Biochemical Technology (BT)
Composition of Committee
prof. RNDr. Ivana Márová, CSc. (předseda) doc. Ing. Pavel Diviš, Ph.D. (místopředseda) prof. Ing. Stanislav Obruča, Ph.D. (člen) prof. Ing. Adriána Kovalčík, Ph.D. (člen) doc. Ing. Eva Vítová, Ph.D. (člen)
Supervisor’s reportIng. Jiří Holub, Ph.D.
Grade proposed by supervisor: A
Reviewer’s reportIng. Jan Obračaj
Grade proposed by reviewer: A
Responsibility: Mgr. et Mgr. Hana Odstrčilová