Extraction and purification of chitinase from Bacillus subtilis

Abstract

Four isolates of Bacillus subtilis produced chitinase were isolated from soil. The bacterial isolates were grown in liquid medium supported with different salts and nitrogen sources. The highest produced isolate was selected for further experiments. Different method was used to purify the enzyme. The optimum condition for enzyme activity was evaluated in present study. B. subtilis A3 gave the highest enzyme production. The different purification steps were followed to purified casein from B. subtilis A3. The produced enzyme was precipitated at 80% of saturated solution of ammonium sulphate. The salt was eradicated by dialyzed the yielded enzyme with distilled water. Finally, the enzyme solution was run through ion-exchange chromatography (Sephadex G-100 column). The maximum specific activity (5.1 U/mg of protein) was observed in liquid medium supported with casein and incubated in 30 oC with pH 8.