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Stanovení aktivity průmyslově významných enzymů produkovaných mikroorganismy izolovanými z potravinového odpadu
Lymarenko, Sofiia
The microbiome and the produced enzymes play an important role in processing food waste. Bacillus licheniformis is one of the representatives of microflora in composting and producer of industrially important hydrolytic enzymes: protease, lipase and cellulase. As part of the thesis, enzymatic activity using spectrophotometric methods was determined in seven strains of B. licheniformis for a period of 96 to 192 hours. In all seven strains, cellulase, protease and lipase activity was detected, which agrees with previously published literature. The highest cellulase activity determined by two methods was recorded for strain 3A-52 (1 U/ml) and 1A-52 (1.5 U/ml) after 24 hours of cultivation. The pH optimum for cellulase activity was 7, and the temperature optimum 50 °C to 60 °C. The maximum protease activity was detected after 120 and 144 hours of cultivation in two strains: 3A-52 (1.3 U/ml) and 3D-42 (1.4 U/ml). During the optimization, it was found that the pH optimum was 9 to 11 and the temperature optimum was 40 to 45 °C depending on the tested strain. The maximum lipase activity was approximately 0.7 U/ml after 144 hours of cultivation in 4D-41 and 3D-42. The temperature optimum was found at 50 to 60 °C and the range of pH optimum for this activity was very wide depending on the studied strain. For the strains with the highest enzymatic activity, a growth curve was determined, where the highest cellulase activity corresponded to the time of transition of the bacterial culture from the exponential phase to the stationary phase, and the highest lipase and protease activities were found later only at the transition from the stationary phase to the death phase. Strain 3A-52 and 3D-42 showed the highest activity for all three monitored enzymes. Subsequently, these strains isolated during composting can be used to produce enzymes industrially.
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Enzymatic modification of Glc-NAc-thiazoline inhibitors of hexosaminidase
Šmeringaiová, Ingrida ; Weignerová, Lenka (advisor) ; Šulc, Miroslav (referee)
This work deals with the problem of searching for effective derivatives of 1,2-dideoxy-2'- methyl-α-D-glucopyranoso-[2,1-d]-Δ2'-thiazoline (NGT), potential inhibitors of human β-N- acetylhexosaminidases. The work is targeted to production of inhibitors derived from NGT by the modification of its structure by free and immobilised lipases. Potential inhibitors of β-N- acetylhexosaminidases may be potent tools for studying of enzymes in cell processes and also open possibility to the discovery of new possible drugs for the treatment of some neurodegenerative diseases, such as Alzheimer disease. The thesis is focused on brief characterization of β-N-acetylhexosaminidases, e.g., glycosidases from enzymatic groups GH 20 and GH 84. β-N-Acetylhexosaminidases from microorganisms Bacteroides thetaiotaomicron, Aspergillus oryzae, Streptomyces plicatus, Talaromyces flavus and humans1 were used in the experiments. The enzymes produced were purified and then tested for their activity. We also tested inhibitory activity of potential inhibitor 6-O-acetyl-1,2-dideoxy-2'-methyl-α- D-glucopyranoso-[2,1-d]-Δ2'-thiazoline. Starting compound, NGT, was synthesized by the modified process (originally created by prof. Knapp2 ) using 2-acetamido-1,3,4,6-tetra-O- acetyl-2-deoxy-α-D-glucopyranose in the reaction with...
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