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

在温带和热带地区对自然界中具有降解二恶英能力的真菌进行了筛选，筛选出了几种真菌。研究了所选真菌对土壤、焚烧灰和水中二恶英的生物修复降解。此外，两种选择的真菌通过原生质体融合形成了具有更高降解二恶英能力的融合体。从自然界中选择的真菌在液体培养基中降解二恶英（2,7- dcdd、2,8- dcdd、2,4,8- tcdf、2,3,7,8- tcdd、2,3,4,7,8- pcdf和OCDD）。培养30 d后，各二恶英的降解程度分别为95%、85%、70%、60%、95%和40%左右。土壤中二恶英（2,7- dcdd、2,4,8- tcdf和2,3,7,8- tcdd）的生物降解可以通过所选真菌进行生物修复。在30 d内，每种二恶英的降解率分别为70%、60%和50%。土壤中约70%的二恶英（污染水平约为1300pg-TEQ/g）通过所选真菌进行30天的生物修复降解。通过生物修复，土壤中约70%的二恶英毒性也被去除。此外，在生物修复过程中，添加表面活性剂可使二恶英的降解程度提高约10%。焚烧灰中约65%的二恶英在60天内通过所选真菌进行生物修复降解。结果表明，经过多次生物修复处理，灰渣中二恶英的降解程度几乎可以完全降解。活性炭吸附二恶英后，将未污染的土壤与吸附的活性炭混合，通过选择真菌进行生物修复，可显著降解水中环境中的二恶英。发现水中的二恶英几乎完全吸附在活性炭上。

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.