Community dynamics in spatially structured microhabitats. (A,B) Schematic (A) and cartoon (B) showing a microhabitat consisting of 85 patches (100 × 100 × 15 μm) connected by corridors (50 × 5 × 15 μm). All 85 patches are connected to growth-medium reservoirs by 180 nm deep slits preventing bacteria from entering the reservoirs but allowing the diffusion of e.g. nutrients and waste. Microhabitats are sealed using a cover slip. (C-H) Kymographs (representing space horizontally and time vertically) of representative sections of microhabitat experiments and the corresponding growth curves in LB (C,F), M9-amino acids (D,G), and M9-glucose (E,H). In all three media, producer (shown in blue) and resistant cells (red) grow readily. Sensitive cells (green) show no growth in LB and M9-amino acids, and sometimes turn filamentous (visible in LB in the connector between the center and rightmost patch). In M9-glucose however, sensitive cells show exponential growth (green line in (H)) in close proximity to producer and resistant cells.