Biodegradation of Oak (Quercus alba) Wood during Growth of the Shiitake Mushroom (Lentinula edodes): A Molecular Approach

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• 作者：Christopher H. Vane ; Trevor C. Drage ; and Colin E. Snape
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2003
• 出版时间：February 12, 2003
• 年：2003
• 卷：51
• 期：4
• 页码：947 - 956
• 全文大小：229K
• 年卷期：v.51,no.4(February 12, 2003)
• ISSN：1520-5118

文摘

The chemical transformations that occur during growth of the shiitake mushroom (Lentinula edodes)on oak (Quercus alba) were investigated to improve mushroom cultivation and utilization of the spentsubstrate. Oak logs were decayed by L. edodes over 8 years, during which time they were sampledat six intervals (30, 40, 66, 76, 77, and 101 months). Fresh and decayed oak samples were analyzedusing solid-state ¹³C NMR and pyrolysis-gas chromatography-mass spectrometry as well as off-line thermochemolysis with tetramethylammonium hydroxide. Degraded oak exhibited lower carboncontents and increased oxygen content compared to the control. Solid-state ¹³C NMR analysis revealedthat polysaccharides were the major component of both fresh and decayed oak but that L. edodesmediated the preferential loss of cellulose and xylans as compared to lignin, which remained in analtered form. Several trends point toward the degradation of lignin, including a decrease in theproportion of syringyl units as compared to guaiacyl units and a reduction in side-chain length. Anincrease in guaiacyl and syringyl acid-to-aldehyde ratios occurred with growth, which suggested thatthe fungus had caused oxidation of C-C bonds. The overall effect of L. edodes on oak is similarto that of many white-rot fungi, which simultaneously degrade all cell wall components.Keywords: Lignin; polysaccharide; degradation; shiitake mushroom; Lentinula edodes; thermochemolysis, pyrolysis; solid-state ¹³C NMR; Quercus alba; oak