Hofrichter M, Ziegenhagen D, Sorge S, Ullrich R, Bublitz F, Fritsche W
Institut fur Technische Mikrobiologie, Friedrich-Schiller-Universitat Jena, Germany.
Appl Microbiol Biotechnol. 1999 Jul;52(1):78-84. doi: 10.1007/s002530051490.
Ligninolytic basidiomycetes (wood and leaf-litter-decaying fungi) have the ability to degrade low-rank coal (lignite). Extracellular manganese peroxidase is the crucial enzyme in the depolymerization process of both coal-derived humic substances and native coal. The depolymerization of coal by Mn peroxidase is catalysed via chelated Mn(III) acting as a diffusible mediator with a high redox potential and can be enhanced in the presence of additional mediating agents (e.g. glutathione). The depolymerization process results in the formation of a complex mixture of lower-molecular-mass fulvic-acid-like compounds. Experiments using a synthetic 14C-labeled humic acid demonstrated that the Mn peroxidase-catalyzed depolymerization of humic substances was accompanied by a substantial release of carbon dioxide (17%-50% of the initially added radio-activity was released as 14CO2). Mn peroxidase was found to be a highly stable enzyme that remained active for several weeks under reaction conditions in a liquid reaction mixture and even persisted in sterile and native soil from an opencast mining area for some days.
木质素分解担子菌（腐朽木材和落叶的真菌）具有降解低阶煤（褐煤）的能力。细胞外锰过氧化物酶是煤衍生腐殖质和天然煤解聚过程中的关键酶。锰过氧化物酶对煤的解聚作用是通过螯合的Mn(III)作为具有高氧化还原电位的可扩散介质来催化的，并且在存在额外的介导剂（如谷胱甘肽）时可以增强。解聚过程导致形成低分子量富里酸类化合物的复杂混合物。使用合成的14C标记腐殖酸进行的实验表明，锰过氧化物酶催化的腐殖质解聚伴随着大量二氧化碳的释放（最初添加的放射性的17%-50%以14CO2的形式释放）。发现锰过氧化物酶是一种高度稳定的酶，在液体反应混合物的反应条件下能保持活性数周，甚至在露天矿区的无菌和天然土壤中能持续存在数天。
