FIG 1.

Pigmentation complementation of mixed strains on blood agar. (A) Reciprocal crossovers of two strains between W50 wbaP and T9SS mutants. The first strain was applied vertically and the second strain was applied in one horizontal motion from left to right on BHI-T BA plates, and plates were incubated for 14 days anaerobically. +, obvious pigmentation; W, weak pigmentation; −, no pigmentation. (B) Two single strains (A and B) were patched on BHI-T BA, and a mix of the two strains was patched in the middle. Three pairs of strains were tested on each plate. The wbaP strain was used as strain A for plate 1, and the wzy strain was used as strain A for plate 2. Strain B was variable for both plates, as indicated. After 6 days’ growth, cells in patches were scraped into 1 ml of PBS and centrifuged to pellet cells. Pellets in centrifuge tubes are shown on the right. All strain names are colored according to strain background to aid matching with Fig. 2.