Institute of Environmental Sciences, Jagiellonian University, 30-387 Kraków, Poland.
Water Sci Technol. 2010;61(3):573-80. doi: 10.2166/wst.2010.868.
We monitored the succession of nitrifiers in a newly opened wastewater treatment plant for five weeks. After the first distinct decrease in total nitrogen, we began monitoring the appearance, size and number of nitrifying bacteria colonies using the fluorescence in situ hybridization (FISH) method. Ammonia oxidizing bacteria (AOB) colonies were visualized under green excitation as red, and nitrite oxidizing bacteria (NOB) colonies were visualized under blue excitation as green. The changes in protozoan community were monitored simultaneously. Ciliates were divided into four functional groups: predatory, bacterivorous free-swimming, bacterivorous crawling, and sessile. The results showed that at the time of the first distinct total nitrogen decrease, the mean length of both AOB and NOB were relatively low, but the colonies, especially those of nitrite oxidizers, were abundant. In time, the distribution of ammonia oxidizer colonies shifted towards larger sizes, but their quantity decreased. In the case of nitrite oxidizers, a similar trend was noticeable but less pronounced. These changes corresponded with an increasing number of crawling bacterivorous ciliates dominated by the "scavenger" genus Aspidisca. The increasing size of nitrifier colonies may have been due to the growing grazing pressure from crawling bacterivorous ciliates. The strong grazing pressure did not negatively affect N-NH(4)(+) removal effectiveness.
我们在一个新建成的污水处理厂监测了硝化菌的演替过程，共持续五周。在总氮第一次明显下降后，我们开始使用荧光原位杂交（FISH）方法监测氨氧化菌（AOB）和亚硝酸盐氧化菌（NOB）的出现、大小和数量。氨氧化菌的菌落用绿色激发光下呈现红色，而亚硝酸盐氧化菌的菌落用蓝色激发光下呈现绿色。同时也监测了原生动物群落的变化。纤毛虫被分为四个功能群：捕食性、自由游动的细菌食性、爬行的细菌食性和固着的。结果表明，在总氮第一次明显下降的时候，AOB 和 NOB 的平均长度都相对较低，但菌落，特别是亚硝酸盐氧化菌的菌落非常丰富。随着时间的推移，氨氧化菌的菌落分布向更大的尺寸转移，但数量减少。对于亚硝酸盐氧化菌，也可以看到类似的趋势，但不太明显。这些变化与数量不断增加的以“清道夫”属 Aspidisca 为主的爬行细菌食性纤毛虫有关。硝化菌菌落的增大可能是由于爬行细菌食性纤毛虫的生长对其产生了更强的摄食压力。强烈的摄食压力并没有对 N-NH(4)(+)去除效率产生负面影响。
