Abundance, Diversity, and Dynamics of Viruses on Microorganisms in Activated Sludge Processes
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Kenichi Otawa [1] ; Sang Hyon Lee [1] ; Atsushi Yamazoe [1] ; Motoharu Onuki [1] ; Hiroyasu Satoh [1] ; Takashi Mino [1]
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[1] University of Tokyo
University of Tokyo
Japón
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- Localización: Microbial ecology, ISSN-e 1432-184X, ISSN 0095-3628, Vol. 53, Nº. 1, 2007, págs. 143-152
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
We examined the abundance of viruses on microorganisms in activated sludge and the dynamics of their community structure. Direct counting with epifluorescence microscopy and pulsed-field gel electrophoresis (PFGE) were applied to 20 samples from 14 full-scale wastewater treatment plants (wwtps) treating municipal, industrial, or animal wastewater. Furthermore, to observe the dynamics of viral community structure over time, a laboratory-scale sequencing batch reactor was operated for 58 days. The concentrations of virus particles in the wwtps, as quantified by epifluorescence microscopy, ranged from 4.2 × 107 to 3.0 × 109 mL−1. PFGE, improved by the introduction of a higher concentration of Tris–EDTA buffer in the DNA extraction step, was successfully used to profile DNA viruses in the activated sludge. Most of the samples from different wwtps commonly had bands in the 40–70 kb range. In the monitoring of viral DNA size distribution in the laboratory-scale reactor, some bands were observed stably throughout the experimental period, some emerged during the operation, and others disappeared. Rapid emergence and disappearance of two intense bands within 6 days was observed. Our data suggest that viruses—especially those associated with microorganisms—are abundant and show dynamic behavior in activated sludge.
