This study suggests a simple three-step screening protocol for the selection of white rot fungi (WRF) capable of degrading polycyclic aromatic hydrocarbons (PAHs), which combines easily applicable bioassay techniques, and verifies that protocol by evaluating the PAH degradation activity, ligninolytic enzyme secretion, and relevant gene expressions of the selected PAH-degraders. Using 120 fungal strains, a sequence of bioassay techniques was applied: Bavendamm's reaction (Step 1), remazol brilliant blue R (RBBR) decolorization (Step 2); assays for tolerance to four mixed PAHs-phenanthrene, anthracene, fluoranthene, and pyrene (Step 3). This stepwise protocol selected 14 PAH-degrading WRF, including Microporus vernicipes, Peniophora incarnata, Perenniporia subacida, Phanerochaete sordida, Phlebia acerina, and Phlebia radiata. Of these, P. incarnata exhibited the highest PAH degradative activity, ranging from 40 to > 90%, which was related to the time-variable secretions of three extracellular ligninolytic enzymes: laccase, manganese-dependent peroxidase (MnP) and lignin peroxidase (LiP). Laccase and MnP production by P. incarnata tended to be greater in the early stages of PAH degradation, whereas its LiP production became intensified with decreasing laccase and MnP production. Pilc1 and pimp1 genes encoding laccase and MnP were expressed, indicating the occurrence of extracellular enzyme-driven biodegradation of PAH by the fungal strains.

中文翻译：

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拟议的逐步筛选框架，用于选择降解多环芳烃（PAH）的白腐真菌。

这项研究提出了一个简单的三步筛选方案，用于选择能够降解多环芳烃（PAHs）的白腐真菌（WRF），该方案结合了易于应用的生物测定技术，并通过评估PAH降解活性，木质素分解酶来验证该方案的PAH降解物的分泌和相关基因表达。使用120种真菌菌株，应用了一系列生物测定技术：Bavendamm反应（步骤1），间苯二酚亮蓝R（RBBR）脱色（步骤2）；测定对四种混合PAHs-菲，蒽，荧蒽和，的耐受性（步骤3）。此分阶段方案选择了14种降解PAH的WRF，包括小孔菌，小尖孢对虾，酸度Perenniporia，Phanerochaete sordida，Plebia acerina和Phlebia radiata。其中，P。incarnata表现出最高的PAH降解活性，范围从40％到> 90％，这与三种细胞外木质素分解酶的时变分泌有关：漆酶，锰依赖性过氧化物酶（MnP）和木质素过氧化物酶（LiP）。在PAH降解的早期阶段，P。incarnata的漆酶和MnP产量倾向于增加，而随着漆酶和MnP产量的降低，其LiP产量会增加。表达了编码漆酶和MnP的Pilc1和pimp1基因，表明真菌菌株发生了细胞外酶驱动的PAH生物降解。锰依赖性过氧化物酶（MnP）和木质素过氧化物酶（LiP）。在PAH降解的早期，P。incarnata的漆酶和MnP产量倾向于增加，而随着漆酶和MnP产量的降低，其LiP产量会增加。表达了编码漆酶和MnP的Pilc1和pimp1基因，表明真菌菌株发生了细胞外酶驱动的PAH生物降解。锰依赖性过氧化物酶（MnP）和木质素过氧化物酶（LiP）。在PAH降解的早期，P。incarnata的漆酶和MnP产量倾向于增加，而随着漆酶和MnP产量的降低，其LiP产量会增加。表达了编码漆酶和MnP的Pilc1和pimp1基因，表明真菌菌株发生了细胞外酶驱动的PAH生物降解。