Elis Nina Herliyana, Achmad, Lucy Andini Novianty and Lendi Forlendiana - 1 Biodegradation on Acacia mangium Willd. and Pinus merkusii Jungh. et de Vriese with Pleurotus spp. Isolates Elis Nina Herliyana 1 , Achmad 1 , Lucy Andini Novianty 1 , Lendi Forlendiana 1 ABSTRACT White-rot fungi Pleurotus spp. was tested to identify the ability of the growth, the colonization and biodegradation on wood of Acacia mangium and Pinus merkusii. This research was carried out in the laboratory of Forest Pathology and Laboratory of Solid Wood, Faculty of Forestry, Bogor Agricultural University, Indonesia. The colonization and biodegradation process of wood that used in this experiment was trapping method. Physiological study was conducted to know the optimum growth of the fungi in glass bottle. Each glass bottle was filled with 40 ml MEA (Malt Extract Agar, with pH 6.0). The fungi was growth on MEA and incubated for eight days at room temperature (29 + o C) and then eight chips of wood (2x3x0.5 cm) was filled in the bottle. The degradation level was counted based on the decreasing of dry weight of wood before and after trapping with the fungi. The incubation periods of trapping method were 0, 2, 4, 6, and 8 weeks. The result showed that the degradation level of P. ostreatus on A. mangium was higher than on P. merkusii at the same treatment. Commonly, the highest degradation level of the fungi on wood in this experiment was occurred two weeks after inoculation. Key Words: Pleurotus spp., P. ostreatus, degradation, Acacia mangium, Pinus merkusii INTRODUCTION Forest with its biodiversity is a very important natural resources of Indonesia. Fungi as one of it, have not been optimized its potentials in Indonesia. Pleurotus spp. as one of white rot fungi can also be used as edible fungi, this fungi are able to degrade lignoselulose materials effective and efficiently. Therefore a research to determine degradation value of this fungi in woody species is needed. 1 Faculty of Forestry, Bogor Agricultural University (IPB) Kampus IPB Darmaga, Bogor, Indonesia