Figure 2
From: Resource limitation drives spatial organization in microbial groups
Growth of colonies of a 1:1 mixture of P. aeruginosa YFP- and CFP-labeled ΔpilB mutants. (a) Images of the edges of colonies at different nutrient concentrations on day 12. White rings show the size of the initial drop; red rings show where our automated image analysis has defined that the two strains have demixed. (b) Colony radius (solid lines) over 14 days (three replicates for each treatment), and the distance between the inoculum and the demixing point (dots). Once segregation has occurred, the demixing distance does not change significantly (discussion in text, Supplementary Figure S4). (c) Heterozygosity H (see Materials and methods, Supplementary Figure S5) of colonies on day 12 as a function of distance from the inoculum. Inset: the demixing distance as a function of nutrient concentration. (d) H on day 12 as a function of time. This is obtained by dividing the x axis in panel (c) by the expansion velocity v of each colony (slope of lines in panel (b)). Inset: the demixing time as a function of nutrient concentration. (c–d) Data show that the demixing point in both time and space correlate with nutrient concentrations.
