降解亚硝酸盐菌种的诱变·纯化及培养基筛选研究

Mutagenesis,purification and Medium Screening of Nitrite Degradation Strains

[目的]筛选出繁殖速度快、降解亚硝酸盐能力强以及经济成本低的优势菌种。[方法]采用诱变和富集培养方法对枯草芽孢杆菌进行改良,筛选出降解亚硝酸盐能力极强的菌株。将株菌分别放在不同浓度的碳源及盐度的培养基中培养,分析其对亚硝酸盐降解能力的影响。[结果]结果表明照射1 min时平板上的菌落数最多,照射时间>6 min可见极少数菌落或几乎不见菌落生长。挑选诱变后的菌落进行室内模拟试验筛选出3株降解亚硝酸盐能力极强的菌种。但倘若培养基中不含糖,降解亚硝酸盐能力就变弱。[结论]不同的紫外诱变时间对枯草芽孢杆菌的生长,以及碳源对菌株降解亚硝酸盐能力均产生明显影响。

[ Objective ] To screen strains with fast reproduction,high ability of nitrite degradation and low economic cost. [ Method] Mutagenesis and enrichment cuhuring methods were carried on the improvement of Bacillus subtilis,strains with high ability of nitrite degradation. Then they were cultured in mediums with different concentrations of carbon source and salinity for analyzing the impact of medium composition on nitrite degradation. [ Result] The maxinmm colonies were obtained at l rain irradiation of plates,and there were very few visible colonies or al- most no colony growth when the exposure time was more than 6 rain. Mutant colonies were selected to do indoor simulation experiment and three strains of highly nitrite degradation ability were obtained, but the degradation ability was very weak if the medium without glucose. [ Conclusion] different UV-induced mutation time effeeted on the growth of Bacillus subtilis significantly, and the impact of carbon source on nitrite degradation were significant.