FIG 6.
Low-nutrient and high-salt conditions are required for interspecies social spreading. (a) Mixed colony on full-strength TSB does not show social spreading. (b) Mixed colony on TSB-NK (10% tryptic soy supplemented with both NaCl and KH2PO4) shows social spreading. (c) Mixed colony on 10% strength TSB shows impaired social spreading. (d) Mixed colony on TSB-N (supplemented with NaCl) exhibits the interspecies social spreading phenotype. For all panels, Pedobacter sp. V48 monoculture is on the top left of the plate, P. fluorescens Pf0-1 is on the top right of the plate, and the mixed colony is in the center. Pictures were taken 144 h after inoculation. Colonies were grown on a 100-mm petri dish.