Abstract:
Laccase is enzyme can be produced by the fungus Trichoderma asperellum
LBKURCC1 that was isolated from cacao rhizosphere soil in Riau plantation area.
This study aimed to determine the optimum pH and temperature for enzymatic
reaction of T. asperellum LBKURCC1 laccase after purification of crude extract
using precipitation ammonium sulfate with a concentration of 20-80%. The
resulting precipitate was dialyzed using ultrafiltration (UF) centrifugation with
30.000 Dalton Molecular Weight Cut Off (MWCO) membrane to obtain partly
purified enzymes. Enzyme activity was measured with a pH variation of acetate
buffer pH 4,0; 4.0; 4.5; 5.0; 5.5 and phosphate buffer pH 6.0; 6.5; 7.0; 7.5; 8.0 and
temperature 30-60oC using buffer obtained from measuring the optimum pH of
laccase. Measuring the enzyme activity using the substrate 2,2'-azinobis-3-
ethylbenzothiazolin-6-sulfonate (ABTS) at a wavelength 420 nm. The results
showed that the optimum laccase activity was found at pH 5.5 (69.50±17.78) U/L
and temperature 45oC (332.87±8.89) U/L.
