Molecular microbial diversity in a nitrifying reactor system without sludge retention

• Published in: FEMS microbiology ecology Vol. 27; no. 3; pp. 239 - 249
• Main Authors: Logemann, Susanne, Schantl, Julia, Bijvank, Saskia, van Loosdrecht, Mark, Kuenen, J. Gijs, Jetten, Mike
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.1998; Blackwell; Oxford University Press
• Subjects: 16S rRNA; Ammonia; Animal, plant and microbial ecology; Bacteria; Biological and medical sciences; Biological effects; Biological treatment of waters; Biotechnology; Cytology; Cytophaga; Denaturing gradient electrophoresis; Ecology; Electrophoresis; Environment and pollution; Fluorescence; Fundamental and applied biological sciences. Psychology; Gel electrophoresis; High temperature; Industrial applications and implications. Economical aspects; Microbial ecology; Microbiology; Microorganisms; Molecular ecology; Morphology; Nitrosomonas; Oligonucleotides; Oxidation; Oxidizing agents; Pictures; Reactors; Retention; rRNA 16S; Sludge; Various environments (extraatmospheric space, air, water); Wastewater; Molecular ecology; 16S rRNA; Denaturing gradient electrophoresis; Ammonium; Nitrobacteraceae; Ribosomal DNA; Genetic diversity; Phylogeny; Biodiversity; Flexibacter; Biological purification; Cytophagaceae; Bioreactor; Nitrification; Nitrosomonas; 16S-RNA; Bacteria; Oxidation; Waste water purification; Cytophagales; Cytophaga; Microbial community
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.1998.tb00540.x

Abstract Recently, the single reactor system for high activity ammonia removal over nitrite (SHARON) process was developed for the removal of ammonia from wastewater with high ammonia concentrations. In contrast to normal systems, this nitrifying reactor system is operated at relatively high temperatures (35°C) without sludge retention. Classical methods to describe the microbial community present in the reactor failed and, therefore, the microorganisms responsible for ammonia removal in this single reactor system were investigated using several complementary molecular biological techniques. The results obtained via these molecular methods were in good agreement with each other and demonstrated successful monitoring of microbial diversity. Denaturing gradient gel electrophoresis of 16S rRNA PCR products proved to be an effective technique to estimate rapidly the presence of at least four different types of bacteria in the SHARON reactor. In addition, analysis of a 16S rRNA gene library revealed that there was one dominant (69%) clone which was highly similar (98.8%) to Nitrosomonas eutropha. Of the other clones, 14% could be assigned to new members of the Cytophaga/Flexibacter group. These data were qualitatively and quantitatively confirmed by two independent microscopic methods. The presence of about 70% ammonia oxidizing bacteria was demonstrated using a fluorescent oligonucleotide probe (NEU) targeted against the 16S rRNA of the Nitrosomonas cluster. Electron microscopic pictures showed the typical morphology of ammonia oxidizers in the majority of the cells from the SHARON reactor.