氨氮对3种吸附态亚硝化单胞菌的抑制动力学

背景] 氨氮浓度会明显影响亚硝化单胞菌的活性，但氨氮浓度对吸附态亚硝化单胞菌菌种的抑制动力学尚缺乏研究。目的] 研究氨氮浓度对3种吸附态亚硝化单胞菌（Nitrosomonas eutropha CZ-4、Nitrosomonas halophila C-19和Nitrosomonas europaea SH-3）的影响。方法] 以碳酸钙作为吸附基质，设定氨氮浓度为25-1 000 mg/L，测定3种亚硝化单胞菌（N.eutropha CZ-4、N. halophila C-19和N. europaea SH-3）的亚硝氮积累速率与最大比生长速率，并通过Edwares2模型建立氨氧化的抑制动力学方程。结果] N. halophila C-19在初始氨氮浓度为50-100 mg/L时的亚硝氮积累最快，N. europaea SH-3的亚硝氮积累则在初始氨氮浓度为50-200 mg/L时最快，而N. eutropha CZ-4则适于在初始氨氮浓度为50-400 mg/L时积累亚硝氮；N. eutropha CZ-4的最大比生长速率出现在初始氨氮浓度为50-400 mg/L时，明显高于N. halophila C-19（25-100 mg/L），而N. europaea SH-3的生长速度在初始氨氮浓度为50-800 mg/L区间内无显著差异；N. europaea SH-3的K_I（922.76 mg/L）显著高于N. eutropha CZ-4（597.88 mg/L），而CZ-4的K_I又显著高于N. halophila C-19（186.24 mg/L），N. europaea SH-3的K_m（72.06 mg/L）显著高于N. halophila C-19（23.23 mg/L）。结论] 3种吸附态亚硝化单胞菌的生长和氨氧化对氨氮浓度变化的响应存在明显差异，对于认识不同亚硝化单胞菌在不同氨氮浓度污水中的功能并开发相应的工程技术具有重要意义。

The NH3-N inhibition kinetics of 3 Nitrosomonas at adhesive status

Background] The activity of Nitrosomonas was significantly influenced by NH₃-N concentration, but the inhibition kinetics of NH₃-N concentration of the adhesive Nitrosomonas were still unknown. Objective] The influence of NH₃-N concentration on 3 strains of adhesive Nitrosomonas (Nitrosomonas eutropha CZ-4, Nitrosomonas halophila C-19 and Nitrosomonas europaea SH-3). Methods] Three strains of Nitrosomonas (N. eutropha CZ-4, N. halophila C-19 and N. europaea SH-3) were cultured under different initial NH₃-N concentrations (ranged from 25-1 000 NH₃-N mg/L) with calcium carbonate as the adsorption matrix. The accumulation rate of NO₂^--N and the specific growth rate were measured, the inhibition kinetic equations of ammonia oxidation were also established by Edwares2 model. Results] The accumulation of NO₂^--N of N. halophila C-19 was fastest when the initial NH₃-N concentration was 50-100 mg/L, while the NO₂^--N accumulation rate was maximum when the initial NH₃-N concentration was 50-200 mg/L for N. europaea SH-3 and 50-400 mg/L for N. eutropha CZ-4, respectively. The maximum specific growth rate of N. eutropha CZ-4 occurred at the initial NH₃-N concentration of 50-400 mg/L, which was much higher than N. halophila C-19 (25-100 mg/L). There was no significant difference in growth rates for N. europaea SH-3 when the initial NH₃-N concentration ranged from 50 mg/L to 800 mg/L. The K_I of N. europaea SH-3 (922.76 mg/L) was significantly higher than N. eutropha CZ-4 (597.88 mg/L), and also the K_I of N. eutropha CZ-4 was significantly higher than N. halophila C-19 (186.24 mg/L). Moreover, the K_m (72.06 mg/L) of N. europaea SH-3 was significantly higher than N. halophila C-19 (23.23 mg/L). Conclusion] The three strains of adhesive Nitrosomonas showed great differences both in ammonia oxidation activity and growth. The results may not only help to understand the functions of different Nitrosomonas in wastewaters with different NH₃-N concentrations, but also contribute to develop corresponding engineering technologies.