Degradation and purification of dioxins by bioremediation with fungi having ability for degradation of dioxins

在温带和热带地区进行了对自然界中具有降解二恶英能力的真菌的筛选，筛选出了几种真菌。用选定的真菌对土壤、焚烧灰烬和水中的二恶英进行了生物修复。此外，通过两种选择的真菌之间的原生质体融合，形成了具有更高降解二恶英能力的融合子1。在液体培养条件下，对2，7-DCDD、2，8-DCDD、2，4，8-TCDF、2，3，7，8-TCDD、2，3，4，7，8-PCDF和OCDD进行了降解。各二恶英的降解率分别为95%、85%、70%、60%、95%和40%。土壤中二恶英(2，7-DCDD、2，4，8-TCDF和2，3，7，8-TCDD)的生物降解可通过选择的真菌进行生物修复。每种二恶英的降解率分别为70%、60%和50%，降解率为30d。土壤中约70%的二恶英(污染程度：约1300pg-TEQ/g)被选定的真菌生物修复30天后降解。通过生物修复，土壤中约70%的二恶英毒性也被去除。此外，在进行生物修复时，添加表面活性剂可使二恶英的降解率提高约10%。经选择的真菌生物修复60d后，焚烧灰中约65%的二恶英被降解。研究发现，通过生物修复的重复处理，灰烬中二恶英的降解程度几乎可以完全降解。选择的真菌对水环境中的二恶英进行生物修复后，再用活性碳吸附二恶英，并将未受污染的土壤与吸附的碳混合，可以显著降解水环境中的二恶英。结果表明，水中的二恶英几乎完全吸附在活性碳上。

Screening of fungi having ability for degradation of dioxins from the nature was conducted in temperate and tropical zone, and selected several fungi. Degradation of dioxins in soils, incinerated ashes and water by bioremediation with the selected fungi was conducted. And, furthermore, formation of fusants having higher ability for degradation of dioxins was conducted by protoplast fusion between the two selected fungi.1. Dioxins (2,7-DCDD, 2,8-DCDD, 2,4,8-TCDF, 2,3,7,8-TCDD, 2,3,4,7,8-PCDF and OCDD) were degraded by the selected fungi from the nature in a liquid medium. The degree of degradation of each dioxin was about 95%, 85%, 70%, 60%, 95% and 40%, respectively for 30 days incubation.2. Biodegradation of dioxins (2,7-DCDD, 2,4,8-TCDF and 2,3,7,8-TCDD) in soils could be degraded by bioremediation with the selected fungi. Each dioxin was degraded about 70%, 60% and 50%, respectively for 30 days.3. About 70% of dioxins in the soils (contamination level: about 1300pg-TEQ/g) was degraded by bioremediation with the selected fungi for 30 days. About 70% of the toxicity of dioxins in the soils was also removed by the bioremediation. And furthermore, the degree of degradation of the dioxins was increased about 10% by addition of a surfactant when the bioremediation was conducted.4. About 65% of dioxins in incinerated ashes was degraded by bioremediation with the selected fungi for 60 days. It was found that the degree of degradation of dioxins in the ashes could be almost completely degraded by the repeated treatment of the bioremediation.5. Dioxins in aqueous environment could be degraded considerably by bioremediation with the selected fungi after adsorption of dioxins by activated carbons and mixing of non-polluted soils with the adsorbed carbons. It was found that dioxins in water were almost completely adsorbed on to activated carbons.