Type 1851

Identification

• Gram variable
• Narrow (about 0.8 µm)
• Commonly has attached growths
• Rectangular-shaped cells
• Identified under 1000x magnification

Why Do I Have It?

• Low F:M conditions
• Occasionally appears alongside high levels of Nocardioforms

Treatment

To reduce the abundance of Type 1851 within a wastewater plant, increase wasting to raise the F:M ratio. Calculate your F:M ratio using the Aquafix F:M ratio calculator. If you have limitations where you cannot increase wasting, the addition of a food supplement/carbon source, such as SmartBOD, is recommended. This particular carbon supplement contains a blend of bioavailable ammonia acids, complex proteins, carbohydrates, and micronutrients targeted to help treat low F:M conditions.

Under the Microscope and in Your Plant

Type 1851 is a narrow (0.8 µm), Gram variable, bulking filament that is 200-400 µm long. Type 1851 can be identified under 1000x magnification. This filament usually has attached growth and tends to be observed in bundles. These bundles can extend from floc, creating unusual arm-like structures. When bundled, the rectangular cells can often be obscured. This filament is frequently seen with Type 0041/0675 as they both thrive in low F:M conditions. Type 1851 can be distinguished from Type 0041/0675 by the narrower cell diameter, its rectangular cell shape, and its tendency to form bundles.

Type 1851 tends to appear in systems with high levels of Nocardioforms. This is because Nocardioforms are able to rapidly uptake BOD, creating the ideal low F:M conditions for Type 1851 to grow. In this situation, treating the Nocardioforms first will help improve low F:M conditions and in turn control the Type 1851 population.