Fig. 5.

Magnitude of cell aggregation for different combinations of ancestral and evolved mutualistic partners from the B2 mutualistic consortium. Cell aggregation was measured as the maximum observed K-value. Definitions: P_anc, ancestral strain of BW25113 (∆proC); T_anc, ancestral strain of BW25113 (∆trpC); P_evol, evolved strain of BW25113 (∆proC); T_evol,a, evolved strain of BW25113 (∆trpC); T_evol,b, evolved strain of BW25113 (∆trpC). T_evol,a and T_evol,b are two genetically different strains of BW25113 (∆trpC) that emerged within the B2 mutualistic consortium. The data are presented as Tukey box plots. Note that the K-values (and thus cell aggregation) were the largest for pairs of evolved mutualistic partners, suggesting that genetic changes in both partners contributed to the observed cell aggregation