239
Views
38
CrossRef citations to date
0
Altmetric
Original Articles

Characterization and Kinetics of 45 kDa Chitosanase from Bacillus sp. P16

, , , , , & show all
Pages 1875-1882 | Received 21 Jan 2003, Accepted 17 Apr 2003, Published online: 22 May 2014
 

Abstract

An extracellular 45 kDa endochitosanase was purified and characterized from the culture supernatant of Bacillus sp. P16. The purified enzyme showed an optimum pH of 5.5 and optimum temperature of 60°C, and was stable between pH 4.5-10.0 and under 50°C. The K m and V max were measured with a chitosan of a D.A. of 20.2% as 0.52 mg/ml and 7.71×10−6 mol/sec/mg protein, respectively. The enzyme did not degrade chitin, cellulose, or starch. The chitosanase digested partially N-acetylated chitosans, with maximum activity for 15-30% and lesser activity for 0-15% acetylated chitosan. The chitosanase rapidly reduced the viscosity of chitosan solutions at a very early stage of reaction, suggesting the endotype of cleavage in polymeric chitosan chains. The chitosanase hydrolyzed (GlcN)7 in an endo-splitting manner producing a mixture of (GlcN)2-5. Time course studies showed a decrease in the rate of substrate degradation from (GlcN)7 to (GlcN)6 to (GlcN)5, as indicated by the apparent first order rate constants, k 1 values, of 4.98×10−4, 2.3×10−4, and 9.3×10−6 sec−1, respectively. The enzyme hardly catalyzed degradation of chitooligomers smaller than the pentamer.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.