Monitoring the community structure of wastewater treatment plants: a comparison of old and new techniques

Abstract

Wastewater treatment is a process of increasing importance in a world with an ever growing human population. Today, most wastewater treatment processes make use of the natural self‐purification capacity of aquatic environments which is the result of the presence and action of microbial communities. Consequently, wastewater treatment facilities are designed to maintain high densities and activities of those microorganisms that satisfy the various purification demands. The performance, at least of large plants, has to be constantly monitored and is subject to strict regulation. Nevertheless, malfunctions resulting in decreased purification efficacy are frequent. This has, over the decades, prompted many microbiologists to compare the structure, dynamics and function of these ‘good’ or ‘bad’, but always complex, microbial communities. Part of these studies was targeted to a basic understanding of the various processes, another part, however, deals with the monitoring of community structure as a means to direct the plant operation towards higher elimination rates and overall stability. Even though the last decade has seen a molecular revolution in microbiology, the standard methods for monitoring wastewater treatment plants still rely on the tools available to the researcher at the beginning of this century, the microscope and agar plates. It is the goal of this MiniReview to compare the potential of the newly available molecular methods with the old monitoring techniques.

Simultaneous Fluorescent Gram Staining and Activity Assessment of Activated Sludge Bacteria

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Bacteriophage predation regulates microbial abundance and diversity in a full-scale bioreactor treating industrial wastewater

“…Many efforts have been made towards better understanding of the mechanisms controlling the microbial ecology of these systems (Amann et al, 1995(Amann et al, , 1998Wagner et al, 2002;Daims et al, 2006;Martín et al, 2006). However, little is known about phage activity in bioreactors, a subject considered, thus far, in only a handful of publications (Ewert and Paynter, 1980;Hantula et al, 1991;Khan et al, 2002a, b;Otawa et al, 2007;Kunin et al, 2008;Wu and Liu, 2009).…”

Comparison of disruption procedures for enumeration of activated sludge floc bacteria by flow cytometry

“…Some studies have demonstrated that the complex structure of activated sludge systems is difficult to assess with traditional techniques (4,5). The emerging molecular techniques used to investigate systems in situ may not completely replace traditional microbiological techniques but will help to identify, monitor, and isolate particular organisms in wastewater systems (6,7).…”