Effects of White and Brown Rot Decay on Changes of Wood Ultrastructure

Piotr Witomski, Wiesław Olek, Jan T. Bonarski

Abstract


Fungal decay results in gradual decomposition of compounds of wood cell walls. Mass loss of wood is usually applied to characterize the decay. However, mechanisms of brown and white rot decay are significantly different, resulting in different degradation of components of wood cell walls. Either type of wood decay should differentially influence wood ultrastructure. The traditionally applied descriptors of wood ultrastructure, i.e. crystallinity, the average spacing of the crystal planes and crystallite size, characterize the ultrastructure in an insufficient way. Crystallographic texture analysis was applied in the present study to characterize changes in wood ultrastructure as a result of brown and white rot decay. The Orientation Distribution Function (ODF) was separately determined for wood decayed by brown rot and white fungi and for several levels of mass loss. A series of crystallographic descriptors was derived from the obtained ODFs. The descriptors consisted of texture index, crystalline volume fraction, and skeleton lines of the ODF. The identified crystallographic orientations confirmed different mechanisms of wood decay for brown and white rot fungi. The observations were supported by different rates of changes of the texture index and evolution of crystalline volume fraction.

Keywords


Crystallographic texture; X-ray diffraction; Scots pine (Pinus sylvestris L.); Wood decay; Coniophora puteana; Trametes versicolor

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Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126