金属离子对粪产碱杆菌C16的脱氮和亚硝酸盐积累的影响

【目的】研究不同金属离子对异养氨氧化细菌C16的生长和脱氮性能影响,探讨适于C16生长和脱氮的金属离子及其浓度。【方法】实验选用Mg2+、Mn2+、Fe2+、Cu2+、Zn2+5种金属离子,对C16的生长﹑脱氮性能﹑亚硝酸盐氮积累以及相关酶活性进行研究。【结果】Mg2+明显促进C16的生长和NH4+-N氧化速率;较高浓度Mn2+使得C16无法生长;原培养基中缺少Fe2+会抑制C16的生长和NH4+-N氧化速率;在原培养基中加入0.1 mmol/L的Cu2+对C16的生长和脱氮具有一定的促进作用,Cu2+使得培养基中基本无NO2--N和NH2OH的积累;不同浓度的Zn2+对C16的生长和氨氮去除有抑制作用。酶活实验结果显示,0.1 mmol/L Mg2+促进了羟胺氧化还原酶(HAO)的活性;0.1 mmol/L Cu2+促进了硝酸盐还原酶(Nar)和亚硝酸盐还原酶(Nir)的活性。【结论】Mg2+是C16生长和脱氮过程中的一种重要金属离子;加入Cu2+可避免过量亚硝酸盐积累。

Influence of metal ions on nitrogen removal and NO2--N accumulation by Alcaligenes faecalis C16

Objective] The influence of different metal ions on the growth and nitrogen removal ability were studied to identify the suitable metal ions and their concentrations for strain C16. Methods] Mg2+, Mn2+, Fe2+, Cu2+ and Zn2+ ions were selected to study their influence on the growth, nitrogen removal ability, NO2?-N accumulation and activity of relative enzymes of strain C16. Results] Mg2+ significantly promoted the growth and NH4+-N oxidation rate of strain C16; C16 could not grow in higher concentrations of Mn2+; lacking of Fe2+ in original medium inhibited the growth and NH4+-N oxidation rate of C16; adding 0.1 mmol/L Cu2+ in the original culture medium could stimulate the growth and nitrogen removal rate of strain C16, meanwhile NO2?-N and NH2OH were only present in trace amounts; the existing of Zn2+ of different concentrations inhibited the growth and NH4+-N oxidation rate of C16. A further enzyme testing results showed that, 0.1 mmol/L Mg2+ promoted the activity of hydroxylamine oxidase (HAO); 0.1 mmol/L Cu2+ promoted nitrate reductase (Nar) and nitrite reductase (Nir) activity. Conclusion] Mg2+ was necessary for the growth and nitrogen removal of strain C16. The addition of Cu2+ could avoid excessive accumulation of nitrite.