Biological Degradation of Chinese Fir with Trametes Versicolor (L.) Lloyd.

Meiling Chen,Chuangui Wang,Benhua Fei,Bo Zhang,Anmin Huang,Xinxin Ma,Shuangyan Zhang

doi:10.3390/ma10070834

Abstract

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) has been an important afforestation species in northeast China. It has obvious defects of buckling and cracking easily, which are caused by its chemical components. Trametes versicolor (L.) Lloyd, a white-rot fungus, can decompose the cellulose, hemicellulose, and lignin in the wood. White-rot fungus was used to biologically degrade Chinese fir wood. The effects of different degradation time on the Chinese fir wood’s mechanical properties, micromorphology, chemical components, and crystallinity were studied. The results showed that the heartwood of Chinese fir was more durable than the sapwood and the durability class of Chinese fir was III. Trametes versicolor (L.) Lloyd had a greater influence on the mechanical properties (especially with respect to the modulus of elasticity (MOE)) for the sapwood. Trametes versicolor (L.) Lloyd degraded Chinese fir and colonized the lumen of various wood cell types in Chinese fir, penetrated cell walls via pits, caused erosion troughs and bore holes, and removed all cell layers. The ability of white-rot fungus to change the chemical composition mass fraction for Chinese fir was: hemicellulose > lignin > cellulose. The durability of the chemical compositions was: lignin > cellulose > hemicellulose. The crystallinity of the cellulose decreased and the mean size of the ordered (crystalline) domains increased after being treated by white-rot fungus.

Highlights

Wood cell walls are the load-bearing unit in trees and can be regarded as laminated nanocomposites, in which cellulose microfibrils are embedded in the matrix of hemicellulose and the lignin is a reinforcement
The wood cell wall mainly consists of cellulose, hemicellulose, and lignin
The heartwood was more durable than the sapwood

Summary

Introduction

Wood cell walls are the load-bearing unit in trees and can be regarded as laminated nanocomposites, in which cellulose microfibrils are embedded in the matrix of hemicellulose and the lignin is a reinforcement. The wood cell wall mainly consists of cellulose, hemicellulose, and lignin. The interaction of chemical components and their mechanical properties leads to specific mechanical properties of wood cell walls and gradually affect the macroscopic properties of wood. The future use of the wood is determined by the wood’s properties. A deep understanding of the structure–property relationship is crucial for understanding the nature origin of the physical and mechanical properties of wood. A better understanding of the properties could give more indications of how to make full use of the wood

Methods

Results

Conclusion