Lignocellulosic polysaccharides and lignin degradation by wood decay fungi: the relevance of nonenzymatic Fenton-based reactions
Lignocellulosic polysaccharides and lignin degradation by wood decay fungi: the relevance of nonenzymatic Fenton-based reactions
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DOI：
10.1007/s10295-010-0798-2
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发表时间：
2011-04-01
影响因子：
3.4
通讯作者：
Goodell, Barry
中科院分区：
文献类型：
--
作者：
Arantes, Valdeir;Milagres, Adriane M. F.;Goodell, Barry
褐腐真菌茯苓和选择性白色腐真菌Perenniporia medulla-panis产生肽和酚盐衍生物化合物作为低分子量Fe 3+还原剂。酚类化合物是两种真菌中具有Fe 3+还原活性的主要化合物，在草酸存在和不存在的情况下，在pH 2.0和4.5下显示Fe 3+还原活性。鉴定了这些化合物的化学结构。与Fe 3+和H2 O2（介导的芬顿反应）一起，它们产生氧自由基，在与体内发现的条件相似的条件下，在体外广泛地氧化木质纤维素多糖和木质素。这些结果表明，除了广泛研究的密粘褶菌-一种模式褐腐菌之外，其他褐腐菌以及选择性的白色腐菌，具有促进芬顿化学降解纤维素和半纤维素以及改性木质素的手段。此外，提供了新的信息，特别是关于木质素是如何攻击，或者重新聚合或溶解取决于真菌攻击的类型，并提出了一个新的途径，选择性白色腐降解木材。讨论了酚类化合物介导的芬顿反应的重要性，以及酚类化合物与褐腐菌中的碳水化合物降解酶和白色腐菌中的木质素修饰酶的单独或协同作用。这项研究提高了我们对环境中碳循环自然过程的理解，这可能有助于探索在生物燃料或聚合物生产中生物转化木质纤维素的新方法，以及开发新的更好的方法来保护木材免受微生物降解。
The brown rot fungus Wolfiporia cocos and the selective white rot fungus Perenniporia medulla-panis produce peptides and phenolate-derivative compounds as low molecular weight Fe3+-reductants. Phenolates were the major compounds with Fe3+-reducing activity in both fungi and displayed Fe3+-reducing activity at pH 2.0 and 4.5 in the absence and presence of oxalic acid. The chemical structures of these compounds were identified. Together with Fe3+ and H2O2 (mediated Fenton reaction) they produced oxygen radicals that oxidized lignocellulosic polysaccharides and lignin extensively in vitro under conditions similar to those found in vivo. These results indicate that, in addition to the extensively studied Gloeophyllum trabeum-a model brown rot fungus-other brown rot fungi as well as selective white rot fungi, possess the means to promote Fenton chemistry to degrade cellulose and hemicellulose, and to modify lignin. Moreover, new information is provided, particularly regarding how lignin is attacked, and either repolymerized or solubilized depending on the type of fungal attack, and suggests a new pathway for selective white rot degradation of wood. The importance of Fenton reactions mediated by phenolates operating separately or synergistically with carbohydrate-degrading enzymes in brown rot fungi, and lignin-modifying enzymes in white rot fungi is discussed. This research improves our understanding of natural processes in carbon cycling in the environment, which may enable the exploration of novel methods for bioconversion of lignocellulose in the production of biofuels or polymers, in addition to the development of new and better ways to protect wood from degradation by microorganisms.