Description
Oral presentation, abstract, conference paperIn recent decades, oligosaccharides derived from chitin and chitosan have gained much attention in many fields i.e. bio-medical, pharmacology, agriculture, and biotechnology. Common procedures for the production of chitooligosaccharides rely on acid catalysis, which is characterised by a low yield and high environmental impact. The use of enzyme catalysis for depolymerisation of chitin and chitosan is a promising alternative to the chemical methods because it allows the production of specific chitooligomers in a controlled way and in an environmentally friendly process. Nevertheless, development of an efficient enzymatic process requires fundamental knowledge of the catalytic mechanisms of enzymes and understanding the interactions between enzyme and their substrate.
In our study we over-expressed and characterised chitinase Chi1 from the fungus Myceliophthora thermophila C1. It was found that chitinase Chi1 is very thermostable and can depolymerise both chitin and chitosan. Furthermore, the degree of acetylation and the Mw of the substrates influenced the chitinase activity and the composition of released oligomers. Chitosans with low Mw and high acetylation degree were degraded faster than chitosans with high Mw and low acetylation degree. The enzyme released mainly dimers from chitin and oligomers with a degree of polymerization (DP) 2 to 12 from chitosan. These oligomers were identified as hetero-oligomers by MALDI-TOF-MS. Chitinase Chi1 degraded fully-acetylated chitooligomers with DP2 to DP6 and the rate increased by increasing DP. Furthermore, oligomers were attacked from their non-reducing end. Products released from chitin and chitosan indicate, that chitinase Chi1 can act on chitin in an exo-manner and on chitosan in an endo-manner. Due to the high thermostability and specific mode of action, chitinase Chi1 seems to be a promising tool for production of N-acetylchitooligosaccharides at industrial scale.
| Period | 28 Aug 2016 → 2 Sept 2016 |
|---|---|
| Event title | 8th International Congress on Biocatalysis |
| Event type | Conference/symposium |
| Location | Hamburg, GermanyShow on map |
| Degree of Recognition | International |