A unifying hypothesis for the structure of microbial biofilms based on cellular automaton models

A review of the basic structure of microbial biofilm reveals that at least three conceptual models exist: (i) heterogeneous mosaic biofilm, (ii) penetrated water-channel biofilm and (iii) dense confluent biofilm. When consideration is given to the effects of growth resource, it may be that all three variants are correct but form at widely different substrate concentrations. Experimental research with bacterial colonies and models of the latter using cellular automata have confirmed this view. Use of cellular automata to model biofilm growth give results which strongly suggest that biofilm structure is largely determined by substrate concentration.