Partial purification of bacterial chitinase as biocontrol of leaf blight disease on oil palm
Chitin is a major component of fungi cell wall, mycelia, stalks and spore which can be hydrolyzed by chitinase. This study was conducted to measure the ability of chitinase producing bacteria in degrading chitin of fungal pathogens such as Curvularia affinis and Colletotrichum gloeosporioides. These pathogens caused antrachnose, leaf blight and rotting on oil palm leaves. Chitinase producing bacteria, Bacillus thuringiensis SAHA 12.08 isolate were used in this study. SAHA 12.08 showed maximum chitinase with specific activity (7.896 U mg-1 protein) at 60 h incubation. Maximum temperature and pH of chitinase activity were 35°C and 7.0, respectively. Chitinase was partially purified by 30% ammonium sulphate precipitation could increase 2.35 fold than the specific activity. The activity of partially purified chitinase was optimal at 45°C and 7.0, respectively. This chitinase was stable at optimum temperature for 180 min incubation. On SDS-PAGE analysis, the enzyme had molecular weight of 107, 102, 82, 63, 55, 46 and 44 kDa from zymogram analysis only 82 kDa protein band showed chitinase activity. In vitro and detached leaf bioassay showed that chitinase of SAHA 12.08 had antagonist activity and biocontrol efficacy to C. affinis and C. gloeosporioides in oil palm leaves.
Research Journal of Microbiology / Academic Journal Inc