by Devac

The results showed that different modes of colony expansion exist, depending on the liquid properties of the growth substrate. To understand how viscosity in the underlying fluid affects colony behavior on the surface, Atis and colleagues tracked fluid motion using florescent beads mixed in with the liquid. What they found is indeed fascinating: the metabolic activity of the colony induces, through a gradient in the nutrient density, fluid flows in the liquid substrate at speeds that far exceed the expansion rate of the colony. These flows, in turn, alter both the colony morphology and the spatial distribution of the different yeast strains.