Biofilms

 A biofilm is an assembly of microbial cells irreversibly connected with a surface (not removed by gentle rinsing) and enclosed in a matrix of primarily polysaccharide material. Depending on the environment in which the biofilm has developed, noncellular materialssuch as mineral crystals, corrosion particles, clay or silt particles, or blood components can also be found in the biofilm matrix. Biofilm-associated organisms also differ from their planktonic (freely suspended) counterparts regarding the transcribed genes. Biofilms can form on a wide range of surfaces, including living tissues, medical devices indoors, industrial or drinking water pipes, or Aquatic system . Biofilms are a group of one or more microorganism forms that can grow on a variety of different surfaces. The biofilm-forming microorganisms include bacteria, fungi , and protists.