The Development of Ddegradation System for Dioxins Using a New White Rot Fungus

1利用转盘式生物反应器，对灰盖鬼伞（Coprinus cinereus）进行了产酶实验。利用得到的粗过氧化物酶，对去除壬基酚和双酚A的处理进行了优化。壬基酚是通过氧化酶反应降解的，但其降解机理与双酚A不同。通过氧化聚合沉淀法去除双酚A。2本研究的目的是利用新筛选的白色腐菌开发一种降解二恶英的生物修复技术。作者尝试筛选二恶英降解微生物，并在1000株菌株中筛选出一株降解能力强的新白色腐烂真菌L-25菌株。通过对该菌株16 rDNA-500序列的分析，发现该菌株为一个与革兰氏菌属（Carbonochaete）相关的新菌株。对该菌株进行了不同条件的培养，得到了大量的锰过氧化物酶。此外，添加蛋白胨，获得高生产率，并产生14 U/mL的锰过氧化物酶。此外，以二恶英为底物，培养该菌株，发现一周内对100 ng/mL的1，3，7，8-四氯二恶英或1，2，7，8-四氯二苯并呋喃的降解率超过60%。二恶英的降解速度比以前的报告快。

1 With a rotating disk bioreactor, the experiment to produce the enzyme -peroxidase-was carried out using a basidiomycete (Coprinus cinereus) culture. Using the crude peroxidase obtained, the treatments to remove nonylphenol and bisphenol A were optimized. Nonylphenol was degraded by an oxidative enzyme reaction, but the mechanism of degradation was different from that of bisphenol A. Bisphenol A was removed by the method of an oxidative polymerization and precipitation.2 The subject of this research is to develop a bioremediation technique for the degradation of dioxins using new screened white rot fungi. The authors attempted to the screening of dioxin degradable microorganisms, and among 1000 strains, a new white rot fungus L-25 strain was screened due to its high degradability. Analyzing the 16rDNA-500 arrangement of this microorganism, we found that it was a new strain related to the genus Phanerochaete. The culture of this strain was carried out at various conditions, and a lot of manganese peroxidase was obtained. Furthermore, adding peptones, a high productivity was obtained, and 14 U/mL of manganese peroxidase was produced. In addition, using dioxins as a substrate and culturing this strain, it was found that more than 60 % of 1,3,7,8-tetrachlorodioxin or 1,2,7,8-tetrachlorodibenzofuran with 100 ng/mL was degraded for one week. This rate of degradation for dioxins is faster than the previous reports.