Karakterisasi Enzim Kitinase dari Bacillus sp. BK17, Isolat Potensial Pengendali Hayati Jamur Patogen Tanaman

KARAKTERISASI ENZIM KITINASE DARI Bacillus sp. BK17, ISOLAT
POTENSIAL PENGENDALI HAYATI JAMUR PATOGEN TANAMAN

ABSTRAK

Karakterisasi kitinase yang meliputi pH dan suhu optimum, Km dan Vmax telah dipelajari
dari isolat Bacillus sp. BK17. Kitinase kasar dari isolat yang dikultur dalam medium
garam minimum dengan kitin koloidal cair selama 5 hari dipresipitasi dengan beberapa
konsentrasi amonium sulfat. Aktivitas kitinase tertinggi didapatkan pada presipitasi
amonium sulfat 50% dengan aktivitas spesifik sebesar 0,545 Unit. Aktivitas enzim
optimum pada pH 6 dan suhu 35 oC yaitu sebesar 0,0750 U/ml. Kitinase Bacillus sp.
BK17 memiliki aktivitas sebesar 0,0112 U/ml pada gerusan miselium Sclerotium
rolfsii. Enzim ini memiliki Km sebesar 0,46 g dan Vmax sebesar 158,73 g.

Kata kunci: Bacillus sp., Kitinase, Sclerotium rolfsii.

Universitas Sumatera Utara

CHARACTERIZATION OF CHITINASE OF Bacillus sp. BK 17,
A POTENTIAL ISOLATE FOR CONTROLLING PLANT PATHOGENIC
FUNGI

ABSTRACT

Characterization of chitinase of including pH and temperature, Km and Vmax of
Bacillus sp. BK 17 has been conducted. Crude extract of Bacillus sp. BK17 growing in
minimum salt medium with colloidal chitin for 5 days was precipited with ammonium
sulphate. Optimum chitinase activity was found in 50% ammonium sulphate
precipitation with specific activity of 0.545 Units. Chitinase activity in homogenated
mycelia of Sclerotium rolfsii was 0.0012 U/ml. The Km and Vmax of the enzyme was
0.46 µg and 158.72 µg, respectively.

Keywords: Bacillus sp. BK 17, Chitinase, Sclerotium rolfsii

Universitas Sumatera Utara