title: Chitinolytic activities of Clostridium sp. JM2 isolated from stool of human administered per orally by chitosan.
abstract: The novel chitinolytic bacterium Clostridium beijerinckii strain JM2 was isolated from the stool of healthy volunteers supplied daily per orally with 3 g of chitosan. The bacterium grown on colloidal chitin produced a complete array of chitinolytic enzymes. Significant activities of endochitinase, exochitinase and chitosanase were excreted into the medium (301, 282 and 268 nkat/microg protein, respectively). The high cellular activity of N-acetyl-beta-glucosaminidase (NAGase) and chitosanase were detected (732.4 and 154 nkat/microg protein, respectively). NAGase activity represented the main activity associated with the cellular fraction. The activities of both enzymes tested increased from 20 to 50 degrees C; the optimum reaction temperature estimated being 50 degrees C. Endochitinase as well as NAGase showed an activity in the pH interval of 4.0-8.0; the optimum pH values were 6.5 and 6.0, respectively. The extracellular endochitinase complex consisted of six isoenzymes with molar mass of 32-76 kDa; in the cellular fraction five bands with molar mass of 45-86 kDa were detected. Exochitinase activity was demonstrated in the form of three bands (with molar mass of 30-57 kDa), NAGase activity displayed one band of 45 kDa.
authors.affiliation: Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czechia. simunek@iapg.cas.cz
authors.forename: J
authors.initials: J
authors.lastname: Simůnek
authors.forename: G
authors.initials: G
authors.lastname: Tishchenko
authors.forename: I
authors.initials: I
authors.lastname: Koppová
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism; D002686:Chitin / Q000378:metabolism*; D002688:Chitinases / Q000378:metabolism*; D048271:Chitosan / Q000008:administration & dosage*; D003013:Clostridium / Q000145:classification / Q000201:enzymology* / Q000254:growth & development / Q000302:isolation & purification; D004795:Enzyme Stability; D005243:Feces / Q000382:microbiology*; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013696:Temperature
chemical_list: D002686:Chitin; D048271:Chitosan; D006026:Glycoside Hydrolases; C019868:chitosanase; D002688:Chitinases; D000118:Acetylglucosaminidase