Spieck Eva, Hartwig Christine, McCormack Iris, Maixner Frank, Wagner Michael, Lipski André, Daims Holger
Universität Hamburg, Biozentrum Klein Flottbek, Mikrobiologie, Ohnhorststr. 18, D-22609 Hamburg, Germany.
Environ Microbiol. 2006 Mar;8(3):405-15. doi: 10.1111/j.1462-2920.2005.00905.x.
Previously uncultured nitrite-oxidizing bacteria affiliated to the genus Nitrospira have for the first time been successfully enriched from activated sludge from a municipal wastewater treatment plant. During the enrichment procedure, the abundance of the Nitrospira-like bacteria increased to approximately 86% of the total bacterial population. This high degree of purification was achieved by a novel enrichment protocol, which exploits physiological features of Nitrospira-like bacteria and includes the selective repression of coexisting Nitrobacter cells and heterotrophic contaminants by application of ampicillin in a final concentration of 50 microg ml(-1). The enrichment process was monitored by electron microscopy, fluorescence in situ hybridization (FISH) with rRNA-targeted probes and fatty acid profiling. Phylogenetic analysis of 16S rRNA gene sequences revealed that the enriched bacteria represent a novel Nitrospira species closely related to uncultured Nitrospira-like bacteria previously found in wastewater treatment plants and nitrifying bioreactors. The enriched strain is provisionally classified as 'Candidatus Nitrospira defluvii'.
此前未培养的属于硝化螺菌属的亚硝酸盐氧化细菌首次成功地从一座城市污水处理厂的活性污泥中富集出来。在富集过程中，类硝化螺菌的丰度增加到细菌总数的约86%。这种高度的纯化是通过一种新颖的富集方案实现的，该方案利用了类硝化螺菌的生理特性，包括通过应用终浓度为50微克/毫升的氨苄青霉素来选择性抑制共存的硝化杆菌细胞和异养污染物。通过电子显微镜、用rRNA靶向探针进行的荧光原位杂交（FISH）以及脂肪酸谱分析对富集过程进行了监测。对16S rRNA基因序列的系统发育分析表明，富集的细菌代表了一种新型硝化螺菌物种，与先前在污水处理厂和硝化生物反应器中发现的未培养类硝化螺菌密切相关。富集菌株暂被归类为“暂定硝化螺菌 defluvii”。
