Dear Marwa,

Sphaerotilus natans is an aquatic periphyton organism associated with polluted water. It forms colonies commonly known as "sewage fungus", but later identified as tightly sheathed filamentous bacteria. Sewage fungus shouldn’t occur in any natural freshwater habitats. Its presence is an indication of a discharge of poorly treated or untreated organic waste.

With my best regards

Prof. Bachir ACHOUR

Sewage fungi consists of filamentous bacteria, associated with fungi and protozoa. It is the slimy growth found in sewage and sewage polluted water. The important examples are: Sphaesolilus natans, Beggiotoa alba, Fusarium aquaeductuum etc. For more details please see the attached pdf.

Fungi is not the only indication of pollution in wastewater. Please refer to:-

https://en.wikipedia.org/wiki/Wastewater_quality_indicators

I agree with answer of Dr. J. C. Tarafdar

hello

Sphaerotilus natans is an aquatic periphyton organism associated with polluted water. It forms colonies commonly known as "sewage fungus", but later identified as tightly sheathed filamentous bacteria.

from this link

https://en.wikipedia.org/wiki/Sphaerotilus_natans

I also recommend Dr. J. C. Tarafdar comment, you are right in your kind agreement dear Dr. Isam.

Warm regards,

Emad

thank you dear doctors for your answers

So, we can not rely on fungi in evaluating water quality, especially if it is not that heavy organic pollution ... am I right ?