Comparison of spatial organization in top-down- and membrane-aerated biofilms: a numerical study

The study of community structure in wastewater biofilms is made difficult by the slow growth rates and high environmental sensitivities of autotrophic nitrifiers. Simulations of such films can generate data quickly and without susceptibility to random environmental perturbation. This study uses a 2D cellular automaton model to compare the community structures of biofilms grown under top-down and membrane aeration conditions. This study found dramatic differences in community structure between the two approaches, most notably the emergence of a niche at the solid–biofilm interface that facilitates the growth of nitrite oxidizing bacteria.