Departamento de Microbiología y Parasitología, Universidad de Alcalá, Alcalá de Henares, Spain.
J Hazard Mater. 2010 Sep 15;181(1-3):181-6. doi: 10.1016/j.jhazmat.2010.04.114.
Advanced oxidation of benzene, toluene, ethylbenzene, and o-, m-, and p-xylene (BTEX) by the extracellular hydroxyl radicals (*OH) generated by the white-rot fungus Trametes versicolor is for the first time demonstrated. The production of *OH was induced by incubating the fungus with 2,6-dimethoxy-1,4-benzoquinone (DBQ) and Fe3+-EDTA. Under these conditions, *OH were generated through DBQ redox cycling catalyzed by quinone reductase and laccase. The capability of T. versicolor growing in malt extract medium to produce *OH by this mechanism was shown during primary and secondary metabolism, and was quantitatively modulated by the replacement of EDTA by oxalate and Mn2+ addition to DBQ incubations. Oxidation of BTEX was observed only under *OH induction conditions. *OH involvement was inferred from the high correlation observed between the rates at which they were produced under different DBQ redox cycling conditions and those of benzene removal, and the production of phenol as a typical hydroxylation product of *OH attack on benzene. All the BTEX compounds (500 microM) were oxidized at a similar rate, reaching an average of 71% degradation in 6 h samples. After this time oxidation stopped due to O2 depletion in the closed vials used in the incubations.
首次证明了白腐真菌糙皮侧耳（Trametes versicolor）通过细胞外羟基自由基（*OH）来氧化苯、甲苯、乙苯以及邻、间、对二甲苯（BTEX）。通过用 2,6-二甲氧基-1,4-苯醌（DBQ）和 Fe3+-EDTA 孵育真菌来诱导 *OH 的产生。在这些条件下，通过醌还原酶和漆酶催化的 DBQ 氧化还原循环产生 *OH。在初级和次级代谢过程中，显示了在麦芽提取物培养基中生长的糙皮侧耳通过这种机制产生 *OH 的能力，并且通过用草酸盐替代 EDTA 和向 DBQ 孵育液中添加 Mn2+ 来定量调节。仅在 *OH 诱导条件下观察到 BTEX 的氧化。通过观察在不同 DBQ 氧化还原循环条件下产生的 *OH 的速率与苯去除的速率之间的高度相关性，以及苯酚作为 *OH 攻击苯的典型羟基化产物的产生，推断出 *OH 的参与。所有 BTEX 化合物（500 μM）以相似的速率氧化，在 6 小时的样品中平均达到 71%的降解。此后，由于在孵育中使用的封闭小瓶中 O2 耗尽，氧化停止。
