Nostocoida limicola I

Nostocoida limicola I is a filamentous bacterium possessing the following characteristics:
- not branched;
- immobile;
- variable filament shape. The filaments can be present in the flocs as well as free in the liquid phase;
- filament length < 200 µm;
- cell diameter 0.6 - 0.7 µm;
- no attached growth;
- no sheath;
- septa not clearly visible;
- no sulphur storage;
- Gram positive;
- Neisser positive. The cells sometimes actually stain grey instead of blue-violet.

N. limicola I resembles M. parvicella and can easily be mistaken for it. The filaments of N. limicola are, however, more robust and the result of Neisser staining is different for this filament. N.B.: See also N. limicola III

Occurrence in activated sludge
N. limicola I occasionally occurs in low loaded domestic plants. It is not known which factors determine the growth of this filamentous bacterium. The presence of N. limicola I results in flotation of the sludge i.e. a scum layer arises. The negative effect on the SVI is small.

Control strategies
It is known that N. limicola I can be controlled by dosing with aluminium salts.
No documented experiences concerning the effect of biological control strategies are known.