Fig. 1.
Interaction between neighboring P. dendritiformis colonies growing on a 1.5% agar gel with 2 g/L peptone nutrient. (A) Images of growing nearby colonies: 9 h after inoculation, no growth; 40 h, the onset of inhibition; 72 h, inhibited growth; 96 h, where growth has stopped in region b but not in regions a and a′. The labels on the x axis indicate the initial distance d between the 2 colonies (here 12 mm); the position xτ(d) is where growth begins to decelerate, and the position xf(d) is where growth stops. (B) Magnified images of region a (uninhibited) and b (inhibited) of A at 96 h show different morphology of both the branches and their interior structures. (C) Colony growth when a glass partition (black line) was inserted midway between 2 inoculation points. There is no growth inhibition: Each colony grew until it hits the partition.