Why do the lower layers of biofilms typically undergo fermen

[ckjavier]

Does it involve surface adhesive fermentation?

[JackBean]

Why do cells undergo fermentation? Which metabolite is in low levels? Do the lower layers have sufficient excess to this metabolite?

[PsycoCarrot]

If I'm not mistaken, the lower levels in a biofilm don't have as much access to oxygen as the outer layers, presumably causing the organisms to switch to fermentative metabolism.

Any other input would be great.