This diploma thesis is focused on study of potential production of extracellular hydrolytic enzymes. The theoretical part deals with characterization of selected hydrolytic enzymes, their catalytic properties, the possibility of extracellular hydrolase production by fungi and their applications. In experimental part production strains Aureobasidium pullulans, Fusarium solani and Phanerochaete chrysosporium were used. Productions of cellulase, amylase, xylanase, lipase, protease and lignin-degraded enzymes (laccase, manganese- dependent peroxidase, lignin peroxidase) were observed. Cultivations were carried out in submersed mode in mineral medium supplemented by waste co-substrates such as wheat bran, corn bran, rice bran and oat bran, sawdust, rice, apple fiber, egg pasta and egg-free pasta. Production of enzymes depended on the substrate type and time of cultivation. The highest cellulase, xylanase and amylase activities were measured in the first period of cultivation (3 to 7 day). Lignin-degraded enzymes and proteases were produced at the end of cultivation (7 to 10 days). Lipolytic activity was detected only in A. pullulans, where the activity increased with time of cultivation. The highest value was determined during cultivation on wheat bran (3.6 nmol/ml.min). The highest xylanase and celulase activity (170.3 nmol/ml.min, 248.0 nmol/ml.min) were determined during cultivation of F. solani on corn bran. The highest amylase activity (111.8 nmol/ml.min) was reported in P. chrysosporium during the cultivation on rice. The highest protease activity (68.0 nmol/ml.min) was determined in F. solani grown on wheat bran. The best producer of laccase was A. pullulans, the highest production was recorded for egg-free pasta (27.0 nmol/ml.min). The maximum lignin peroxidase activity (12.5 nmol/ml.min) was measured during the cultivation of F. solani on egg pasta, while the highest yield of Mn-dependent peroxidase (7.7 nmol/ml.min) was achieved during the cultivation of A. pullulans on wheat bran. Lignin-degraded enzymes behaved as inductive, while the other enzymes were produced in mineral medium too. Activity of cellulase in the mineral medium was in A. pullulans strain higher than in media with waste substrates. Enzymes produced into A. pullulans medium were purified by ultrafiltration, ion exchange chromatography and gel filtration.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:216760 |
| Date | January 2011 |
| Creators | Skoumalová, Petra |
| Contributors | Čarnecká, Martina, Márová, Ivana |
| Publisher | Vysoké učení technické v Brně. Fakulta chemická |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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