Comparison of the Ability of Several White-rot Fungi to Biobleach Acacia Oxygen-delignified Kraft Pulp
Sitompul Afrida
STT Migas, Jalan Soekarno Hatta Kilometer 8, Balikpapan 76125, East Kalimantan, Indonesia and Department of Bioscience and Chemistry, Hokkaido University, N9W9, Kita-ku, Sapporo 060-8589, Japan.
Toshihiro Watanabe
Department of Bioscience and Chemistry, Hokkaido University, N9W9, Kita-ku, Sapporo 060-8589, Japan.
Yutaka Tamai *
Department of Forest Science, Hokkaido University, N9W9, Kita-ku, Sapporo 060-8589, Japan.
*Author to whom correspondence should be addressed.
Abstract
Previous screening analyses demonstrated that the in vivo biobleaching activities of the white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 are higher than those of Phanerochaete chrysosporium and Trametes versicolor. The purpose of the current study was to examine the production of extracellular enzymes of these four white-rot fungi grown on three types of low-cost media containing agricultural and forestry waste, and to evaluate the ability of the produced extracellular enzymes to biobleach Acacia oxygen-delignified kraft pulp (A-OKP). The biobleaching activity of extracellular fractions of I. lacteus, L. tigrinus, T. versicolor, and P. chrysosporium cultures was the most pronounced after 3 days of incubation with Acacia mangium wood powder supplemented with rice bran and 1% glucose (WRBG) with resultant Kappa number reduction of 4.4%, 6.7%, 3.3%, and 3.3%, respectively. Therefore, biobleaching ability of I. lacteus and L. tigrinus have been shown to be higher than of T. versicolor and P. chrysosporium, both in vivo and in vitro.
Keywords: White-rot fungi, acacia kraft pulp, biobleaching, kappa number