Lignin degradation in wood-feeding insects
Lignin degradation in wood-feeding insects
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DOI：
10.1073/pnas.0805257105
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发表时间：
2008-09-02
影响因子：
11.1
通讯作者：
Tien, Ming
中科院分区：
文献类型：
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作者：
Geib, Scott M.;Filley, Timothy R.;Tien, Ming
芳香族聚合物木质素保护植物免受大多数形式的微生物侵袭。尽管大量被降解的木质纤维素都经过节肢动物的肠道，但木质素在这些系统中的命运尚不清楚。利用氢氧化四甲基铵热化学裂解技术，我们发现两种昆虫——亚洲长角甲虫（光肩星天牛）和太平洋湿木白蚁（窄颈弓背蚁）能够降解木质素。在甲虫和白蚁体内，都检测到显著水平的丙基侧链氧化（解聚）以及环甲氧基的去甲基化；对于白蚁，还观察到环羟基化。此外，对光肩星天牛肠道真菌群落进行不依赖培养的分析，确定了茄病镰刀菌/赤球丛赤壳菌复合种中的一个单一真菌物种。这是一种可能有助于木材降解的软腐真菌。这些结果改变了我们对食木昆虫降解木质素的理解。
The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of A. glabripennis identified a single species of fungus in the Fusarium solani/Nectria haematococca species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects,