3-D Multi-Species Biofilm Models F. Gao, X. Zhong, H. La, S. Krone, L. Forney

Model based on nutrient diffusion and energy allocation (1) (2) (3)

nutrient diffusion Nutrient concentration in bulk liquid is set to be constant and normalized to 1.0; Nutrient diffuses vertically through biofilm, from top down; A site obtain nutrients diffusing from a cone-shaped region above the site a site

Birth rate Allows multiple nutrients Metabolism Effects of environment on growth rate Nutrient Energy Maintenance Stress response Growth ATP Conversion coefficient

Placement of offspring Growth is suppressed if all neighboring sites are occupied Daughter cell placed at vacant direct neighbor chosen at random If no direct neighbors available, 2 nd direct neighbors considered 6 direct nbrs 26 2 nd direct nbrs

Death rate Death rate increased if a cell fails to get enough energy for maintenance and stress response Death rate is proportional to the gap between the energy demand & actual energy available

Collapse Maximum thickness Self regulation afterbefore

simulations 3 species: 2 aerobic and 1 anaerobic 2 aerobic species 2 species: 1 aerobic and 1 anaerobic randomly initialized