Purification and characterization of alkaline chitinase from Paenibacillus pasadenensis CS0611

An extracellular chitinase produced by Paenibacillus pasadenensis CS0611 was purified by ammonium sulfate precipitation, HiTrap DEAE FF and HiLoad 26/600 Superdex 200pg column chromatography. The apparent molecular mass determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis was 69 kDa. The optimum pH and optimum temperature of the chitinase were 5.0 and 50 degrees C, respectively. The enzyme showed high stability at alkaline pH values and temperatures below 40 degrees C. Additionally, the metal ions Mn2+, Mg2+, and Co2+ inhibited activity of the chitinase. The chitinase was active on colloidal chitin with an apparent K-m of 4.41 mg/mL and V-max of 1.08 mg/min. Substrate spectrum analysis indicated that the chitinase reacted preferentially with the glucosidic bond between GlcNAc-GlcNAc. The enzymatic hydrolysate was analyzed by high-performance liquid chromatography and thin layer chromatography, and clearly showed that a subunit of (GIcNAc)(2) was the main hydrolysis product. (C) 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.