对防腐处理前后遭细菌侵蚀的木材超微构造研究

ULTRASTRUCTURE STUDIES ON THE ATTACK OF UNTREATED AND NCA-TREATED WOODS BY TUNNELLING BACTERIA

用透射电镜观察了隧道式细菌在未经防腐剂处理的素材和处理过的木材[欧洲白桦(Betula pendula),欧洲赤松(Pinus silvestris)和挪威云杉(Picea abies)]中形成的腐朽现象,研究了细菌入侵木材细胞壁的过程。侵蚀是从木材细胞腔内开始,通过S_3层后,细菌在细胞壁的S_1层、S_2层及胞间层内移动并且分裂,引起木材细胞壁的降解。还观察了隧道式细菌、隧道的形态和超微结构。本研究表明具缘纹孔和单纹孔的纹孔膜比纹孔缘对细菌活动更有抗性。细菌可以侵入低浓度防腐剂(0.5％Tanalith NCA)处理过的木材,表明细菌具一定解毒能力。

Tunnelling bacteria (TB) decay of the untreated and preservative treated hardwood (Betula pendula) and softwood (Pinus silvestris, Picea abies were was examined with TEM. The mechanism of bacterial entrance into the wood cell wall was studied. TB attack on the cell wall begins from the lumen side. The degradation of cell wall is caused by bacteria moving and dividing within the S_1, S_2 layers of the cell wall. The morphology and ultrastructure of TB and their tunnels was observed. The present work shows that the membrances of the bordered pits and simple pits appear having the capability to resist bacterial action, but bordere and the other part of cell wall are not. As TB can attack the wood treated by 0.5% Tanalith NCA, TB has a cabability of detoxic.