丝状真菌F54的分离鉴定及其对铯的吸附特性

从新疆放射性污染土壤样本中,采用微生物分离方法,结合压力试验及吸附实验,获得一株对放射性核素污染具有修复能力的土著丝状真菌F54。通过形态学、分子生物学鉴定及Biolog碳源利用实验,F54为镰刀霉菌属真菌,与Fusarium oxysporum strain ATCC MYA-3931同源性最高。最适宜生长条件是:马铃薯葡萄糖培养基,30℃,pH=7.0。菌株F54吸附Cs+的最佳条件是:pH=7.0,30℃,伴随生长进行吸附约3~4d,吸附率最高能达到约84%,常见金属阳离子K~+、Na~+、Ca~(2+)、Mg~(2+)、Al~(3+)、Fe~(3+)对其吸附均有一定的抑制作用。菌株F54能够耐受10kGy的钴源照射,对重金属离子Ni~(2+)、Cr~(3+)、Zn~(2+)、Co~(2+)、Pb~(2+)、Hg~(2+)均有较高耐受性,对放射性137 Cs的吸附率为62%。菌株F54在有较高的重金属离子混合污染的放射性环境中具有一定的修复应用潜能。

Isolation and Identification of Filamentous Fungi F54 and Its Biosorption and Enrichment Characteristics of Cesium

In order to obtain indigenous strains with radionuclide remediation ability in radioactive pollution area in Xinjiang, soil samples were collected for separation of microorganisms. After the pressure tests and adsorption experiments, a filamentous fungus F54 was finally obtained. Through the traditional morphology and molecular biology identification, strain F54 belongs to Fusarium sp., exhibits the highest homology with Fusarium oxysporum strain ATCC MYA-3931. The optimum growth condition is: potato dextrose medium, pH=7.0. The optimum absorption conditions of Cs⁺ for F54 strain are: pH=7.0, 30 ℃, 3-4 d associated with the growth. The Cs⁺ adsorption efficiency of F54 can up to be about 84% tested by ICP-MS. Common cations such as K⁺, Na⁺, Ca²⁺, Mg²⁺, Al³⁺, Fe³⁺ can inhibit the adsorption of Cs⁺. The F54 strain can tolerate 10 kGy dose irradiation of radioactive cobalt, and also has high tolerance of heavy mental ions Ni²⁺, Cr³⁺, Zn²⁺, Co²⁺, Pb²⁺, Hg²⁺. The adsorption efficiency of radioactive ¹³⁷Cs can up to be 62% tested by liquid scintillator. Strain F54 has high potential to repair radioactive pollution in heavy metal contaminated environment.