WOOD DECAY BY BROWN-ROT FUNGI - CHANGES IN PORE STRUCTURE AND CELL-WALL VOLUME
WOOD DECAY BY BROWN-ROT FUNGI - CHANGES IN PORE STRUCTURE AND CELL-WALL VOLUME
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DOI：
10.1515/hfsg.1991.45.5.383
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发表时间：
1991-10-01
期刊：
影响因子：
2.4
通讯作者：
HIGHLEY, TL
中科院分区：
文献类型：
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作者：
FLOURNOY, DS;KIRK, TK;HIGHLEY, TL
在土块培养中，甜桉木块被茯苓（Postia）胎盘腐蚀。在不同的失重情况下，衰变被终止，并且四种低分子量分子（水，4埃；葡萄糖，8埃；麦芽糖）的孔体积可用。10埃;和棉子糖，12埃)和三个右旋糖(M(r) 6,000, 38埃；11200,51埃；和17500,61埃)用溶质排斥法测定（Stone and Scallan 1968b）。七个探针可以接触到的未腐烂木材的体积从三个最大的1.0 ml g-1到水的1.35 ml g-1不等。因此，在健全的木材中，归因于管腔、坑和其他大开口的体积为1.0 ml g-1，细胞壁中可接触到水的体积为0.35 ml g-1。在这个体积中，80%是直径为bbb12埃的分子所不能接近的。随着木材的腐烂，在失重35%时，细胞壁气孔体积稳定增加到0.7 ml g-1。四种低分子量探针可以接触到新的细胞壁体积，但M(r)大于或等于6000的分子不能接触到。四种最小探针的可达孔体积逐渐增大。由于降解过程中组分的去除而产生的新细胞壁体积大部分在12 ~ 38埃的孔径范围内。在实验误差范围内。在完好或腐烂的木材中未观察到bb0 ~ 38埃的孔隙。我们的结果与假设一致，即纤维素的初始解聚，棕色腐病的特征，是由扩散剂引起的。该药剂的分子直径显然在12埃到38埃之间，它会引起侵蚀，从而扩大它所能进入的孔隙。
Sweetgum (Liquidambar styraciflua L.) wood blocks were decayed by Postia (= Poria) placenta in soil-block cultures. Decay was terminated at various weight losses, and the pore volumes available to four low molecular weight molecules, (water, 4 angstrom; glucose, 8 angstrom; maltose. 10 angstrom; and raffinose, 12 angstrom) and three dextrans (M(r) 6,000, 38 angstrom; 11,200, 51 angstrom; and 17,500, 61 angstrom) were determined by the solute exclusion technique (Stone and Scallan 1968b).The volume in sound (undecayed) wood that was accessible to the seven probes varied from 1.0 ml g-1 for the three largest to 1.35 ml g-1 for water. Thus, the volume in sound wood attributable to lumens, pits, and other large openings was 1.0 ml g-1 and that accessible to water in the cell wall was 0.35 ml g-1. Of this volume, 80% was inaccessible to molecules > 12 angstrom in diameter. As the wood was decayed, the volume of pores in the cell wall increased steadily to 0.7 ml g-1 at 35% weight loss. New cell wall volume was accessible to the four low molecular weight probes but not to molecules of M(r) greater-than-or-equal-to 6,000. The increase in accessible pore volume to the four smallest probes was gradual. Most of the new cell wall volume created by removal of components during decay was in the pore size range of 12 angstrom to 38 angstrom. Within experimental error. no pores of > 38 angstrom were observed in sound or decayed wood. Our results are consistent with the hypothesis that the initial depolymerization of cellulose, characteristic of brown rot, is caused by a diffusible agent. The molecular diameter of the agent is apparently in the range 12 angstrom to 38 angstrom and it causes erosion and thus enlargement of the pores to which it has access.