Prasetyorini, Hadisty Dian2021-12-272021-12-272021-06wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10348Lacasse is an enzyme that requires additional chemical components (non protein) such as metal ions to increase its activity. This research aim to determine the effect of the addition of metal ions Mg2+, Mn2+ and Ca2+ to laccase enzyme activity produced by the Trichoderma asperellum LBKURCC1 using ABTS as a substrate. The concentration of each metal ions is 2 mM. The laccase enzyme activity assay was measured using a UV-Vis spectrophotometer with a wavelength of 420 nm and incubated for 0, 5 and 10 minutes. The highest laccase enzyme activity was obtained at 5 minutes incubation for the addition of Ca2+ metal ions, with the value is 3,7064 x 10-3 U/mL which is able to increase lacasse activity by 73,97%. The addition of Mn metal ions causes a decrease in laccase activity by 13.89% from the control with the resulting activity of 1.8611 x 10-3 and which is possible due to the effect of heavy metals.enABTSLacassemetal ionTrichoderma asperellumArticle