Fig. 1

The Flow cell system. Panel a Fluidic units with syringes (left) connected to µ-slides mounted in the microscope (right). The syringes are filled with medium that flows continuously over a growth chamber in the µ-slide. Panel b Close-up of the four growth chamber µ-slides. Panel c Micrograph of biofilm structures with a characteristic tail formed in the growth chamber after 20 days of flow, 10× magnification. The red arrow indicates the flow direction. Example from a lignin-enriched compost biodiversity. Image credit: Gunhild Hageskal