Induction and Purification of a Thermophilic Chitinase Produced by Aeromonas sp. DYU-Too7 Using Glucosamine

다국어 초록 (Multilingual Abstract)

In the presence of chitin, Aeromonas sp. DYU-Too7 can produce extra-cellular, chitin-degrading enzymes. Chitin analogues and other carbon sources can be used to cultivate this bacterial strain. The chitinases produced by the strain were higher in the GIcN (glucosamine) medium than those in other media. The maximal chitinase activity occurred in the medium containing 0.1% GlcN. Cultivation of Aeromonas sp. DYU-Too7 in the GlcN medium sped up the chitinase production; however, the same result did not appear when it was cultivated in the (Chitin + GlcN) medium. This result may indicate that GlcN can be utilized by Aeromonas sp. DYU-Too7 as a carbon source and an inducer to produce chitinases. A chitinase with a molecular mass of 36 kDa was further purified and characterized to have an optimal reacting pH of 5.0 and an optimal reacting temperature of $50^{\circ}C$. This chitinase showed high stability in the proximity of $30^{\circ}C$ and also high stability in the proximity of pH 7.0. The hydrolysates of colloidal chitin, with the aid of the 36-kDa chitinase, were analyzed by an HPLC and found to be chitobiose.