Interactions of bacteria to bacteria and bacteria to substrate surface as revealed by perturbing the formation of micro-colonies.

<p>Bacterial divisions and development into micro-colonies were carried out on a layer of thin agar immersed in LB with a coverslip-sandwiched chamber as that in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048098#pone-0048098-g002" target="_blank">Fig. 2</a>. The chamber was lightly tapped and responses of the bacteria were immediately followed by time-lapsed microscopy. Arrowheads indicate those bacteria stayed attached to the surface but turning and vibrating could be seen with many of these cells. Arrow highlights bacteria behaving as a group that restructured their gross morphology, from a spindle-like structure (A) transiting into a near spherical shape (C), and re-positioned themselves actively (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048098#pone.0048098.s007" target="_blank">Movie S1</a> in Data S1). Note: no apparent bacterial division could be seen within this short period of 6 seconds. Scale bar: 10 µm.