Mechanism of high antifungal effect of chitosan-metal salts of newly developed wood-preservative on wood.

本研究提出了与Dr.T.合作开发的新型木材防腐剂壳聚糖金属盐（CCS）对木材具有高抑菌作用的机理。小林，东洋木材防腐制品公司。SEM-WDXA分析了CCS有效成分（金属铜）在CCS处理木块中的微分布（局部），以及TYP （Tyromyces palustris）在CCS处理木块中的真菌行为与铜金属分布的关系。结果表明，即使经JIS- a9201（1991）风化处理，铜金属仍与JIS木材试样细胞壁表面紧密结合，并定位于管胞的开口管腔表面和射线薄壁细胞或轴向薄壁细胞内的管腔表面。当CCS防腐剂应用于实尺度木材时，铜金属仅沉积在处理木材表面部分的少数细胞层中。然而，经过CCS处理的木材对TYP真菌的攻击表现出明显的高抵抗力。TYP菌丝在射线薄壁细胞和轴向薄壁细胞中被选择性抑制，通过对TYP腐烂木材的扫描电镜观察证实了这一点。从这些证据可以看出，CCS处理与CCA处理有着根本的区别，即前者是“特定细胞表面粘附（沉积）型”，而后者是“全细胞壁浸渍型”。与CCA处理相比，CCS处理以最少的铜金属量表现出较高的抗真菌效果，CCS处理所需的化学物质几乎是CCA处理的十分之一。综上所述，从安全性和有效性两方面考虑，新开发的CCS木材防腐剂将被大力推荐作为后cca。

In this study, the auther proposed a mechanism of high antifungal effects of chitosan-metal salts (CCS) on wood, which was newly developed wood-preservative in cooperation with Dr.T.Kobayashi, Toyo Wood Preservative Company. The micro-distribution (localization) of the CCS's effective component (copper metal) within the CCS-treated wood specimens, and the fungal behavior of TYP (Tyromyces palustris) within the CCS treated wood blocks in related to the copper-metal distribution by means of SEM-WDXA.As results, the copper metals were firmly bonded to the cell wall surfaces of the JIS wood-specimen even after the JIS-A9201 (1991) weathering treatments, and were localized on the opened lumen surfaces of the tracheids and selectively on the lumen surfaces within the ray parenchyma cells or axial parenchyma cells. When the CCS preservative was applied to the real-scaled timbers, the copper metals were only deposited in the few cell layrs at the surface portion of the treated timber. Nevertheless, the CCS treated woods showed prominently high resistance against the TYP fungal attacks. The TYP hyphae were inhibited selectively in the ray parenchyma cells or axial parenchyma cells, that was clalified by the SEM observation of the TYP rotted woods. Judgging from these evidences, it is clear that the CCS treatment were fundamentally differed from the CCA treatment, that is, the former is "specified cell surface adhere (deposition) type", but the latter is "all cell wall impregnation type". Then, the CCS treatments exhibited the high antifungal effects by means of the least amount of the copper metals in comparison with the CCA treatment, the requried chemicals of the CCS treatment were almost one tenth of the CCA treatment. As conclusion, newly developed CCS wood preservative will be strongly recommended as the post-CCA,because of both sides from safeness and effectiveness.