The Microbiology of Wastewater

Biological wastewater treatment would be impossible without microorganisms. Wastewater treatment plants are huge microbiological powerhouses, where microorganisms are responsible for the conversion of compunds and degradation of pollutants. Disturbances of the plant are usually based on disturbances of its microbial processes. Therefore, knowing the plant's biocenosis and thus being able to control its processes is essential.

Operational Safety by Direct Insight

Action instead of reaction - direct insight into the wastewater treatment plant and monitoring its bacterial populations allow prompt intervention and action before process problems make an obvious impact. This leads to a prevention of operational problems and a significantly increased plant safety. Additional side-effects are an improvement of the plant's economic efficiency and protection of the environment.

Wastewater foaming problems
Problems with foaming
Microthrix filaments shine red after analysis with VIT® gene probe technology
Detection of Microthrix with VIT® gene probe technology

Why can't wastewater bacteria be detected by conventional methods?

Conventional detection of bacteria is based on the work of Robert Koch and is not adequate for
the analysis of complex samples like wastewater. Scientific studies prove that up to 99,9% of all wastewater bacteria are non-cultivable. Due to their lack of specificity and the morphological variability and gram variability of bacteria, basic staining methods are also insufficient.

Therefore it is necessary to analyze bacteria directly in the activated sludge. The VIT® gene probe technology is hereby the only method which allows the direct and highly-specific detection of viable bacteria in the wastewater sample. The bacteria can be identified and quantified.

What are VIT® gene probes?

Gene probes are tiny bits of genetic material, coupled with a dye. They enter and attach themselves to bacteria. Subsequently, the cells start to shine. Gene probes are designed to detect only specfic bacteria species or groups of bacteria. As a result, up to 100% of all known an unknown wastewater bacteria can be detected.

VIT® gene probes technology used on bacteria
Figure: The dye is specificallly introduced into the bacteria. Bacteria can subsequently be identified due to their glow.

Shining bacteria

The term "shinig bacteria" describes the glowing of bacteria due to their intracellular dye content. By this glowing signal, bacteria can be detected quickly and specifically.

Bacteria in activated sludge

Activated sludge typically contains up to 5 billion bacteria per ml. The bacteria have an average size of 2-3 µm.

  • shape: "anything goes" -> rods, cones, filaments, spirilla etc.
  • generation times (how fast bacteria duplicate): a few minutes up to several days
  • up to 99,9% non-cultivable: do not grow on nutrient media
  • the majority of bacteria lives in wastewater flocs

VIT® Early Warning System

The VIT® Early Warning System, which consists of different products and services, all relevant microbiological topics in wastewater can be analzsed and optimized

Degradation performance/ Populations
Sludge bulking and foaming
Biological phosphorus removal
Anaerobic reactor and anaerobic sludge



Support in the battle against bulking and floating sludge – the new VIT® product Chloroflexi allows a fast detection and quantification of filamentous bacteria of the Chlorflexi group and Eikelboom Type 1851.

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The new product VIT® PAO/GAO enables specific dectection of bacteria responsible for biological phosphate removal in wastewater treatment plants.

[…] more

Detection of legionella in the effluent of wastewater treatment plants is problematic due to the accompanying bacterial flora. With VIT®, however, it is fast and reliable..

[…] more


Our practical workshop "Microbiology of wastewater" provides a well-balanced mix of theory and practice, including insight into your own samples, as well as know-how according to the lastest scientific findings.

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Get an overview of the publications dealing with the application of our technology in wastewater and request further information.

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VIT® early warning system

Learn more about the VIT® early warning system and find out how it can help you with further imporoving your plants' operational safety.

VIT® early warning system