CELL BIOMASS DETERMINATION IN SEWER BIOFILMS AND A MONOSPECIES PSEUDOMONAS PUTIDA BIOFILM

In biofilms, cells are embedded in a matrix of extracellular polymeric sub­stances (EPS). The relative quantity of cell biomass and EPS varies largely in different biofilms. The cell biomass can account for 10-90% of the organic matter (Nielsen et al., 1997). The amount of EPS is important for many biofilm properties, e.g., strength, volumetric specific activity and effective diffusion coefficient in the biofilm. If these parameters are to be determined precisely in biofilm experiments, it is important to be able to divide total biofilm bio­ mass into cell biomass and an EPS fraction.