You are reading nitrosomonas europaea doesnt like light? Im reading that it lives on sides of buildings in polluted cities
But that doesnt mean a whole lot, it could still very well not like light, but it doesnt need darkness
Also, you suggested that nitrosomonas europaea will attempt to hide in sludge
which does not in any way suggest it creates sludge, only that if sludge is around, it will hide in it.
But according to my understanding of how bacteria works, it still needs to stay in contact with an ammonia supply, namely the water. So trapped in the middle of sludge, unless the sludge itself is the ammonia supply, it would starve
and if the sludge is the ammonia supply, then there still needs to be bacteria elsewhere eating up ammonia thats in the water
We all talk about our bacteria as if there are just tons and tons of the stuff
But if you think about it, it a healthy / mature / cycled tank
there is no detectable level of ammonia
so how much bacteria does it take to consume an undetectable level? Probably not very much