Pemurnian Parsial dan Karakterisasi Kitinase Asal Jamur Entomopatogen Beauveria bassiana Isolat BB200109

Abstract

<p>Beauveria bassiana is one of the<br />entomopathogenic fungus that produces chitinase when<br />infecting its host. This study was aimed to purify, isolate and<br />characterize chitinase of B. bassiana isolate BB200109.<br />Pathogen identity was determined both morphologically and<br />molecularly using ITS primer, whilst characterization was<br />done at various conditions i.e. temperature, pH, metal ion<br />and incubation time. Results showed that the BB200109<br />isolate belonged to B. bassiana. The isolate produced<br />extracellular chitinase with chitinolytic index of 1.035. Partial<br />purification of three saturated ammonium sulphate<br />precipitation (10, 30, and 70%) showed maximum purity of<br />1.2 times, while dialysis could increase the purity of 1.9<br />times compared to that of crude enzyme extract.<br />Characterization results showed that the chitinase isolated<br />from B. bassiana isolate BB200109 had an optimum activity<br />at pH 4, temperature 50oC, and optimum incubation time of<br />90 minutes. The effect of metal ions (60 mM) Mn2+ served as<br />activator, while EDTA, K+, Mg2+, Cu2+, Fe2+, Zn2+, and Na+<br />acted as inhibitors. The chitinase demonstrated lower<br />affinity to chitin substrate as indicated by high Km value of<br />0.266 mg/l and a Vmax of 0.067 mg/l sec. Based on SDS-PAGE,<br />chitinase from B. bassiana isolate BB200109 had molecular<br />weight of 60.25 kDa. The study implied the potency of<br />B. bassiana isolate BB200109 as extracellular chitinase<br />producer with its enzyme charateristics seems to be<br />developed as an insect biocontrol agent.</p>