光电子响应微生物的筛选鉴定及生长代谢特征研究

Screening of Photoelectron-response Microbes as well as Their Growth and Metabolism

筛选可良好响应半导体光电子的微生物菌株,在矿物与微生物交互作用研究中应用前景广阔。从某铀尾矿土壤中,利用含有半导体材料Ti N营养成分1/2、1/4、1/8、1/10、1/50、1/100和1/1 000的培养基在光照条件下筛选出光电子响应的菌株;通过形态特征、生理生化和分子系统学对菌株进行鉴定,并用紫外-可见吸收光谱和三维荧光光谱测试分析该菌株在光电子作用下生长情况以及蛋白质、腐殖酸等代谢产物的变化。结果显示,从土壤中筛选出一株对光电子具有较强响应效果的菌株Y-5,经鉴定为粪产碱杆菌(Alcaligenes faecalis)。该菌株在1/10底物浓度中由于营养丰富光电子作用并不明显,在1/50,1/100较低底物浓度中营养贫乏,光电子作用加速了该菌生长速率,代谢产物蛋白质、腐殖酸也相应增加。从土壤筛选得到的光电子响应微生物菌株粪产碱杆菌,光电子能促进其生长代谢。该方法在定向筛选光电子响应的菌株方面具有一定的可行性。

Screening microbial strains that have promising response to semiconductor photoelectron brings broad application prospectsin the study of interaction between minerals and microorganisms. Using the uranium tailing area soil,the microbial strains with photoelectronresponse were screened in the media of containing 1/2,1/4,1/8,1/10,1/50,1/100,and 1/1 000 semiconductor material Ti N underillumination condition. Then the strain was identified through its morphological,physiological and biochemical characteristics,and themolecular phylogeny. Ultraviolet-visible absorption spectra and three-dimensional fluorescence spectra were used to analyze the growth ofthe strain and the changes of protein,humic acid,and other metabolites. The strain Y-5 screened from soil was identified to be Alcaligenes faecalis,which had strong response to photoelectron of Ti N. The optoelectronic effect was not obvious due to rich nutrient in the 1/10 substrateconcentration;but in 1/50 and 1/100 low substrate concentration,the growth rate was accelerated by photoelectron due to poor nutrient,andthe protein and humic acid increased correspondingly. A photoelectron-response microbial strain A. faecalis was screened from an uraniumtailing area soil,and the photoelectron promoted its growth and metabolism. This method demonstrated certain feasibility in screening thephotoelectron-response.