紫外诱变法提高好氧反硝化菌降解性能的研究

Improving Degradation Ability of an Aerobic Denitrifer by Ultraviolet Mutagenesis

采用紫外诱变方法对从污水处理厂活性污泥中筛得的1株好氧反硝化菌(YS)进行处理,得到1株突变菌株(TB),考察了诱变前后2菌株的理化性能及反硝化能力的变化.结果表明,菌株TB的反硝化能力得到改善.在相同实验条件下,菌株TB对硝酸根的去除能力可从菌株YS的87%提高至93%,培养基中的亚硝酸根浓度从212.48 mg.L-1减少到37.62 mg.L-1,去除率从15%快速提高至85%,表明菌株TB对亚硝酸根的去除能力大幅提高,且传代前后菌株TB对硝酸根和亚硝酸根的去除率变化不大,遗传稳定性较好.对两菌株的反硝化性能影响因素的研究比较发现菌株YS的最适条件为:接种量1.5%左右,pH为6,C/N比为10,碳源为葡萄糖;而菌株TB的最适条件为:接种量1.5%左右,pH为9,C/N比为10,碳源为琥珀酸钠.

An aerobic denitrifier（YS） isolated from swage was mutagenized by UV-irradiation and a high-nitrogen-removal mutant（TB） was obtained.Differences between these two strains in physical and chemical properties and denitrification capacity were studied.The results showed that the denitrification capacity of mutant strains TB was improved.Under the same conditions,the nitrate removal capacity of TB increased from 87% to 93%,and the nitrite concentrations in medium from 212.48 mg·L-1reduced to 37.62 mg·L-1,the removal of nitrite increased rapidly from 15% to 85%,indicating that the strain of TB on the nitrite removal capacity was greatly improved.There was little change in the capacity of the nitrate and nitrite removal after passage,so the genetic stability of TB was better.The effects of different factors on denitrification were investigated and the results were that the optimal culture condition of original strain YS were 1.5% inoculum concentration,pH 6,C/N ratio=10,and carbon source was glucose;the optimal culture condition of mutant strain TB were 1.5% inoculum concentration,pH 9,C/N ratio=10,and carbon source was sodium succinate.