A new acid stable exo--1,3-glucanase of Rhizoctonia solani purified from a commercial source

22 A new acid stable exo--1,3-glucanase of Rhizoctonia solani purified from a commercial source 23 „Kitarase-M‟, by a combination of ammonium sulfate precipitation, ion-exchange and gel filtration 24 methods, had specific activity 0.26 U/mg protein, Km and Vmax values of 0.78 mg/ml and 0.27 mM/min/mg 25 protein, respectively. It had molecular weight of 62 kDa with optimum activity at 40°C temperature and pH 26 5.0, with high stability at pH of 3-7. Unique amino acid sequence was found at N-terminal end. The 27 substrate specificity studies confirmed that it is an exo--1,3-glucanase. It could hydrolyze curdlan powder 28 to release glucose. 29 30