P40: Production and partial characterization of chitosanases produced by Paenibacillus ehimensis

It is known that chitosanolytic enzymes can be potentially used in the preparation of chitosan oligomers. In this work, we describe the partial characterization of extracellular chitosanases group produced by the bacterium Paenibacillus ehimensis. For the chitosanases procuction, the cells were grown in medium containing chitosan (3g.L^-1), yeast extract (6g.L^-1), magnesium sulfate heptahydrate (0.5g.L^-1), potassium dibasic phosphate (1g.L^-1) and glucose (1g.L^-1) at 36°C with stirring at 120rpm for 2 days. Evaluation of enzyme activity was carried out by the incubation of enzyme extract (250 μL) with 1% chitosan solution (250 μL, pH 6.0). The reaction tubes were incubated at 55°C for 30 min. After incubation the amount of reducing sugar released was measured by a Dinitrosalicylic Acid Method (DNS) with glucosamine as the calibration standard. The effect of temperature and pH on the stability of these enzymes was studied by incubating the crude extract in the temperature range from 30°C to 55°C and pH 4 to 10. Results showed high stability in temperature studied as well as with pH between 5.0 and 8.0. Additionally, was investigated the action of organic solvents (methanol, ethanol, acetone, butanol, toluene, ethyl acetate and acetonitrile), divalent ions and other chemical agents (EDTA, Mg²⁺, Cu²⁺, Fe²⁺, Ca²⁺, Zn²⁺, Mn²⁺, Ba²⁺ and sodium dodecyl sulfate) on the activity of these enzymes, demonstrating high stability of these crude complexes and dependence of Mn²⁺. The use of enzymes with high stability even in its crude form may facilitate their application in industry by the reduction of time and cost.