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  4. Extrazelluläre Chitindeacetylase mariner und terrestrischer Bakterien
 
Zitierlink URN
https://nbn-resolving.de/urn:nbn:de:gbv:46-diss000104971

Extrazelluläre Chitindeacetylase mariner und terrestrischer Bakterien

Veröffentlichungsdatum
2006-10-13
Autoren
Schmietenknop, Bernd  
Betreuer
Widdel, Friedrich  
Gutachter
Siefert, Eike  
Zusammenfassung
The aim of this work was to find a bacterial catabolic enzyme, suitable for the deacetylation of chitin to chitosan. This enzyme, called chitin deacetylase, is known to be present in fungi but not in bacteria. To find such an enzyme we first had to isolate bacteria which are able to grow on chitin.From marine sediments and also from compost, enriched with chitin, several bacteria strains were isolated on chitin plates or on acetate, the second product of a chitin deacetylase besides chitosan.Some of the strains were tested for chitin deacetylase activity with a colorimetric test or with a test for the formation of acetate. Regarding the advantages of an extracellular enzyme for a technical process (the purification of the enzyme is easier), the screening methods were designed to detect extracellular enzymatic activity in the culture media. A few strains had chitin deacetylating activity but the best results were those of strain 99.6. This strain had also a chitinase activity. The cda-encoding gene of this strain was cloned into E.coli at the Fraunhofer Institute in Hannover.First investigations with 99.6 were done to optimize the culture conditions for a technical process. We also tried to reduce chitinase activity by UV-induced mutations. But after this, also the deacetylating activity was much lower. Trying to concentrate the ezyme we recognized that the enzyme is very unstable. Most of its activity was lost during centrifugation or freezing.
Schlagwörter
chitin deacetylase

; 

chitin

; 

chitosan

; 

bacteria

; 

isolation
Institution
Universität Bremen  
Fachbereich
Fachbereich 02: Biologie/Chemie (FB 02)  
Dokumenttyp
Dissertation
Zweitveröffentlichung
Nein
Sprache
Deutsch
Dateien
Lade...
Vorschaubild
Name

00010497.pdf

Size

3 MB

Format

Adobe PDF

Checksum

(MD5):4dd5508a4c56754b34f8c1fee7ffb575

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