Sliekers A Olav, Haaijer Suzanne C M, Stafsnes Marit H, Kuenen J Gijs, Jetten Mike S M
Department of Biotechnology, Faculty of Applied Science, Delft University of Technology, Julianalaan 67, 2628 BC, Delft, The Netherlands.
Appl Microbiol Biotechnol. 2005 Oct;68(6):808-17. doi: 10.1007/s00253-005-1974-6. Epub 2005 Oct 13.
In natural and man-made ecosystems nitrifying bacteria experience frequent exposure to oxygen-limited conditions and thus have to compete for oxygen. In several reactor systems (retentostat, chemostat and sequencing batch reactors) it was possible to establish co-cultures of aerobic ammonium- and nitrite-oxidizing bacteria at very low oxygen concentrations (2-8 microM) provided that ammonium was the limiting N compound. When ammonia was in excess of oxygen, the nitrite-oxidizing bacteria were washed out of the reactors, and ammonium was converted to mainly nitrite, nitric oxide and nitrous oxide by Nitrosomonas-related bacteria. The situation could be rapidly reversed by adjusting the oxygen to ammonium ratio in the reactor. In batch and continuous tests, no inhibitory effect of ammonium, nitric oxide or nitrous oxide on nitrite-oxidizing bacteria could be detected in our studies. The recently developed oxygen microsensors may be helpful to determine the kinetic parameters of the nitrifying bacteria, which are needed to make predictive kinetic models of their competition.
在自然和人工生态系统中，硝化细菌经常处于氧气受限的环境中，因此必须竞争氧气。在几个反应器系统（恒化器、恒浊器和序批式反应器）中，只要铵是限制性氮化合物，就有可能在极低的氧气浓度（2 - 8微摩尔）下建立好氧铵氧化菌和亚硝酸盐氧化菌的共培养物。当氨的含量超过氧气时，亚硝酸盐氧化菌从反应器中被冲洗出来，铵主要被与亚硝化单胞菌相关的细菌转化为亚硝酸盐、一氧化氮和一氧化二氮。通过调节反应器中的氧铵比，这种情况可以迅速逆转。在分批和连续试验中，我们的研究未检测到铵、一氧化氮或一氧化二氮对亚硝酸盐氧化菌有抑制作用。最近开发的氧微传感器可能有助于确定硝化细菌的动力学参数，而这些参数是建立其竞争预测动力学模型所必需的。
