CONCEPTUAL-MODEL FOR PRODUCTION AND COMPOSITION OF EXOPOLYMERS IN BIOFILMS

The presence and the transformations of organic fractions within biofi lms are not usually included in biofilm models, mainly owing to the la ck of knowledge of the important processes, the stoichiometry and the kinetics. A conceptual biofilm model taking into account microbial phy siology with regard to production of extracellular polymers and their transformation within the biofilm is suggested. The suggested componen ts in the biofilm are the cell biomass and the various extracellular p olymeric substances (EPS), such as polysaccharides, protein, humic sub stances and nucleic acids. In addition, environmental factors that inf luence the microbial exopolymer production and composition are taken i nto account. The suggested conceptual model can be helpful in structur ing the design and evaluation of biofilm experiments focusing on biofi lm structure and properties. (C) 1997 IAWQ. Published by Elsevier Scie nce Ltd.