Isolation of White Rot Fungi from Rotten Wood from Bogor Botanical Garden in Indonesia and its Ligninolytic Enzymes Activity

Abstract

Background: White rot fungus is one of the microorganisms that can naturally decompose lignocellulosic biomass. Indonesia's nature with its tropical forests has enormous potential for the development of white rot fungi that can be used as biological resources, one of which is in the bio delignification process. This paper aims to study the isolation and qualitative and quantitative screening of ligninolytic enzymes from white rot fungi found on rotten wood. Methods: In this study, white rot fungus was isolated from rotten wood from Bogor Botanical Gardens area, Indonesia. The isolated fungus were screened qualitatively by the Bavendamm test and decolorization of Remazol Brilliant Blue R test. Furthermore, the activity of laccase enzymes, manganese peroxidase and lignin peroxidase were measured by UV-Vis Spectroscopy. Laccase enzyme as an enzyme that has the highest activity is produced in liquid media containing rice husks and purified and its activity is measured. Result: The results showed that of the 5 isolates that were positive for Bavendamm test and decolorization of RBBR test, they were KRB1, KRB8, KRB9, KRB10 and KRB12. The highest laccase activity was produced by isolates KRB 12 at 8244.72 U/ml. Laccase was purified by precipitation of ammonium sulfate at a saturation level of 0-80%. Laccase was precipitated optimally in ammonium sulfate saturation 0-20%. The overall yield of the purification was 44.92%, with a purification fold of 1.72 and a specific activity of 5579.95 U/mg protein. Conclusion: The result for isolate KRB12 laccase as compared of the reported laccases suggests isolate KRB12 is a potential isolate for the production of laccase enzymes. Key words: White rot fungi, Isolation, Bavendamm test, Decolorization of RBRR, Laccase, Manganese peroxidase, Lignin peroxidase