Figure 5.

Effects of dksA1 gene mutation on various bacterial motilities. A, swimming motility tested on LB plates with 0.3% agar. Attenuated swimming motility is shown as the reduced size of the circular colonies of dksA1 mutants. The plate was incubated at 30 °C for 24 h without being inverted. B, twitching motility tested on an LB plate with 1% agar. Reduced size of the twitch zone is shown in ΔdksA1 and ΔdksA1ΔdksA2 mutants. The plate was incubated at 37 °C for 24 h without being inverted. The plate was stained with Coomassie Blue for better visualization of the twitch zone. C, swarming motility tested on a swarm plate. Formation of a characteristic irregular branch was not observed in ΔdksA1 or ΔdksA1ΔdksA2 mutants. The swarm plate consisted of M8 salt, 0.1% glutamate, 0.25% glucose, and 0.5% agar. Bacterial strains were inoculated on the surface of the swarm plate and incubated at 30 °C for 24 h without being inverted. D, swarming motility of the dksA1-complemented strains. The irregular branches reappeared when the dksA1 gene was complemented.