Combined Molecular and Conventional Analyses of Nitrifying Bacterium Diversity in Activated Sludge: Nitrosococcus mobilis and Nitrospira -Like Bacteria as Dominant Populations

作者：Stefan Juretschko, Gabriele Timmermann, Markus Schmid, Karl‐Heinz Schleifer, Andreas Pommerening‐Röser, Hans‐Peter Koops, Michael Wagner · 发表于：Applied and Environmental Microbiology · 年份：1998 · DOI：10.1128/aem.64.8.3042-3051.1998 · 被引用次数：804 · 研究领域：Wastewater Treatment and Nitrogen Removal、Microbial Community Ecology and Physiology、Protist diversity and phylogeny

The ammonia-oxidizing and nitrite-oxidizing bacterial populations occurring in the nitrifying activated sludge of an industrial wastewater treatment plant receiving sewage with high ammonia concentrations were studied by use of a polyphasic approach. In situ hybridization with a set of hierarchical 16S rRNA-targeted probes for ammonia-oxidizing bacteria revealed the dominance of Nitrosococcus mobilis-like bacteria. The phylogenetic affiliation suggested by fluorescent in situ hybridization (FISH) was confirmed by isolation of N. mobilis as the numerically dominant ammonia oxidizer and subsequent comparative 16S rRNA gene (rDNA) sequence and DNA-DNA hybridization analyses. For molecular fine-scale analysis of the ammonia-oxidizing population, a partial stretch of the gene encoding the active-site polypeptide of ammonia monooxygenase (amoA) was amplified from total DNA extracted from ammonia oxidizer isolates and from activated sludge. However, comparative sequence analysis of 13 amoA clone sequences from activated sludge demonstrated that these sequences were highly similar to each other and to the corresponding amoA gene fragments of Nitrosomonas europaea Nm50 and the N. mobilis isolate. The unexpected high sequence similarity between the amoA gene fragments of the N. mobilis isolate and N. europaea indicates a possible lateral gene transfer event. Although a Nitrobacter strain was isolated, members of the nitrite-oxidizing genus Nitrobacter were not detectable in the activat...