Utilization of Leiotrametes menziesii BRB 73 for Decolorization of Commercial Direct Dyes Mixture with Different Culture Conditions

Mycoremediation is classified as an inexpensive, environmentally friendly, and effective technique to reduce wastewater. Leiotrametes menziesii BRB 73 was one of the White Rot Fungi (WRF) that has the potential to degrade dyes. Suitable environmental conditions can optimize dye decolorization results. This study aims to investigate optimal environmental conditions such as time incubation, concentration of dyes, pH, CuSO4, and glucose concentration against decolorization of a mixture of direct dyes and enzyme activity (laccase and MnP). The mixture of commercial direct dyes used contains direct turquoise (DT), direct orange (DO), and direct yellow (DY) dyes. Decolorization was measured using a spectrophotometer at 400-700 nm. Laccase and MnP assay using ABTS and 2.6 DMP as substrate, respectively. The highest decolorization by Leiotrametes menziesii BRB 73 was produced at 54.3% at 96 hours and increased to 67% at a dye concentration of 500 mg.L-1. Meanwhile, the highest laccase and MnP activities were 215 U.L-1 and 39 U.L-1, respectively. pH range was quite wide, ranging from pH 5.5-9, supported by stable MnP activity from pH 3-7. CuSO4 inducers were not required for the decolorization of these dyes. Decolorization was optimal at the addition of 1% glucose, while enzyme activities were 0.5% glucose. Decolorization of dyes by Leiotrametes menziesii BRB 73 was indicated through degradation pathways involving laccase and MnP enzymes. This isolate has a high tolerance to dye concentrations, a wide pH range, and low carbon requirements. Thus, it was recommended as a mycoremediation agent.