vermicon News

Candidatus Nitrotoga was discovered in Siberian permafrost 10 years ago. Today, we know that this remarkable bacterium is a key player in biological nitrogen elimination – reliable, efficient and resilient. Whether at low temperatures or under extreme conditions, Nitrotoga ensures stable nitrification when other bacteria have long since failed. It belongs to the class of Betaproteobacteria within the Phylum Proteobacteria and has the amazing ability to oxidize nitrite even under unfavorable conditions.

Cold? No problem for Nitrotoga!

Nitrotoga can show its full strength in biological wastewater treatment, especially at low temperatures, because these bacteria are still active when other nitrite oxidizers have long since given up. It can even tolerate temperatures as low as 2–6 °C.

Nitrite oxidation under extreme conditions

But low temperatures are not the only thing that Nitrotoga can withstand. It is also much less sensitive to high concentrations of FA (free ammonia) and FNA (free nitric acid) than other nitrite oxidizers. FA can inhibit both AOB (ammonium-oxidizing bacteria) and, in high concentrations, NOB (nitrite-oxidizing bacteria). Accumulated nitrite in turn leads to the formation of free nitric acid, which is directly toxic to the NOB. Nitrotoga shows clear advantages here due to its particular resilience. But Nitrotoga is also less sensitive to low oxygen concentrations, high sulfide concentrations and pH fluctuations.

Practical due to robustness

The special feature of Nitrotoga, which is not only able to survive under extreme conditions but also to oxidize nitrite efficiently, makes it particularly suitable for stabilizing nitrification at winter temperatures and in industrial wastewater treatment plants.

In summary, Nitrotoga remains active and efficient even under extreme challenges:

• Temperatures of 2–6 °C
• High FA concentrations (free ammonia)
• High FNA values (free nitric acid)
• Low oxygen concentrations
• High sulfide levels and pH fluctuations

Why monitor Nitrotoga?

Monitoring Nitrotoga can be used to evaluate the ability of the wastewater treatment plant to maintain nitrification even under difficult conditions. Nitrotoga is therefore an excellent indicator of the nitrification resilience of the plant. Likewise, the identification and reliable quantification of Nitrotoga allows the success of measures to be evaluated that aim to enrich Nitrotoga in the system by changing the process control.
 

NEW: VIT® Nitrotoga – detection and quantification of Nitrotoga

The new VIT® Nitrotoga test kit is available in time for the start of the winter months. The new test kit not only allows the highly specific identification of Candidatus Nitrotoga bacteria in wastewater, but also their quantification. Using VIT® Gene Probe Technology, all nitrite oxidizers except Nitrotoga are directly and specifically stained in green in the sample. At the same time, all bacteria of the genus Nitrotoga are stained in red. This method can be used to determine both the total amount of Nitrotoga in the activated sludge and its specific proportion of nitrite oxidizers. VIT® Nitrotoga helps to evaluate the robustness of plant nitrification for cold seasons and harsh conditions and allows the success of enrichment conditions to be verified.

The advantages of VIT® Nitrotoga:

• Direct identification and quantification of Candidatus Nitrotoga
• Visualization directly in activated sludge
• Optimal control of nitrification resilience
• Evaluation of the success of enrichment measures

Webinar in 2025

A webinar is planned for 2025 on the role of Nitrotoga and Comammox bacteria in biological wastewater treatment plants. Date will be announced.