Delignification of Valuable Timbers Decayed by India Lignicolous Fungi

Abstract

Wood degrading capacity of lignicolous fungi was studied by decay test. In which two methods were followed, i) wood chips method ii) wood block method. Eight timbers infected by six fungi were selected for studying percentage of decay and biochemical test was done to know delignification. After 12 months, 90 % of wood block of T. arjuna was decayed by L. stereoides. In teak wood 16.82 % of decay was due to H. apiaria in 3 months. As the percentage of moisture was less, percentage of weight loss was also less; this indicated that decay capacity of fungi will depends on % moisture content in wood. The percentage loss in hot water soluble substrates was more in case of T. crenulata due to L. stereoides for 5 months, whereas lowest in case of teak wood decayed by H. apiaria for 5 months. The percentage loss in ethanol benzene soluble substrate was more in case of Adina wood decayed by C. versicolor for 5 months, whereas lowest in case of teak wood infected with L. stereoides for 3 months. As the incubation period increases, percentage loss in acid soluble lignin was more in case of infected woods. L. stereoides, C. versicolor, and H. apiaria showed selective delignification in all infected woods, whereas T. pini showed simultaneous degradation of lignin in all woods tested. The valuable timber like teak wood was not resistant to wood decay because they loss 50% of lignin. The in vitro wood decay test can‟t be taken as absolute evidence for wood decay behavior of lignin-degrading fungi, so we should conform decay of wood by consider biochemical test. For rapid evaluation of wood decay the wood chip method was best suitable. For the first time the wood decay and biochemical test of 8 wood samples infected by white rot fungi like S. commune, L. stereoides, H. apiaria, C. versicolor, T. pini and soft rot fungi like T. viride was studied.