The morphology and bacterial function of these biofilms are not fully understood. Biofilm is a general term that applies to any microbial community attached to a solid surface. Biofilms produce a matrix of polysaccharide fibers. These sticky fibers allow bacteria to adhere to one another and anchor them to a surface. This seemingly random structure is actually highly organized.
Water flows through the biofilm.
This allows for the delivery of nutrients and the removal of wastes. It is essentially a circulatory system. Moreover, some bacteria feed off the waste products of others. Some bacteria ingest dead cells. This highly complex microbial ecology can be harnessed for wastewater treatment.