Dependence of Local Cell Density on Concentric Ring Colony Formation by Bacterial SpeciesBacillus subtilis

Abstract

The formation of concentric ring-like colonies by bacterial species Bacillus subtilis has been investigated, focusing our attention on the effect of local cell density upon the bacterial motility: (i) Neither any chemicals nor a pacemaker at the center of the ring takes part in the concentric ring formation. (ii) Phase entrainment between two colonies having different phase of concentric ring does not occur. (iii) From the measurement of lag-phase time when varying the initial cell density, the start of the first migration phase is found to depend on the cell density. (iv) When cutting the part of a colony which is behind a migration phase just after the start of migration, the migration phase becomes shorter. On the other hand, the following consolidation phase becomes longer. (v) By the replica-printing method, active bacteria move collectively from inside to outside of the outermost consolidation terrace. Our present experimental results are qualitatively consistent with the results of the other bacterial species P. mirabilis, although the individual cell motility is quite different from each other. The present results suggest that the essential factor of the change of the bacterial motility of B. subtilis during concetric ring formation is the local cell density.

Cell population heterogeneity during growth of Bacillus subtilis

“…5A). Furthermore, whereas swarming in wild-type cells is preceded by a lag period that is dependent on the number of cells used in the inoculum (Kearns and Losick 2003;Shimada et al 2004), the swarming lag of DS526 was found to be dependent on the IPTG concentration. Indeed, at the highest levels of inducer, the swarming lag was completely abolished (Fig.…”

Molecular characterization of midgut bacteria of Aedes albopictus exhibiting swarming motility property

“…After the mixing of purified bacterial isolates, this property was not regained, this occurred because they might not be in such a proportion which is required for the production of sufficient amount of surfactant. It has been reported that different bacterial colonies produce different swarming patterns, which depends on the condition of environment where they are growing (Shimada et al, 2004, Hiramatsu et al, 2005. The bacteria MS1-8 was isolated from midgut of Ae.…”

Statistical Features of Complex Systems –Toward Establishing Sociological Physics–

“…Figure 11 shows a typical morphological diagram of Bacillus subtilis colonies obtained as a function of both C n and the inverse of C a . 7,[52][53][54][55][56][57][58] The diagram is divided into five regions by the pattern characteristics of bacterial colonies: regions A (DLA), B (Eden), C (concentric ring), D (homogeneously spreading disk), and E [dense branching morphology (DBM)]. Here we focus on the growing colonies in region D and investigate the size distribution of bacterial cells inside the colonies.…”