Tata Institute of Fundamental Research, Hyderabad 500107, India.
Phys Rev E. 2018 Jan;97(1-1):012413. doi: 10.1103/PhysRevE.97.012413.
Bacteria, while developing a multicellular colony or biofilm, can undergo pattern formation by diverse intricate mechanisms. One such route is directional movement or chemotaxis toward or away from self-secreted or externally employed chemicals. In some bacteria, the self-produced signaling chemicals or autoinducers themselves act as chemoattractants or chemorepellents and thereby regulate the directional movements of the cells in the colony. In addition, bacteria follow a certain growth kinetics which is integrated in the process of colony development. Here, we study the interplay of bacterial growth dynamics, cell motility, and autochemotactic motion with respect to the self-secreted diffusive signaling chemicals in spatial pattern formation. Using a continuum model of motile bacteria, we show growth can act as a crucial tuning parameter in determining the spatiotemporal dynamics of a colony. In action of growth dynamics, while chemoattraction toward autoinducers creates arrested phase separation, pattern transitions and suppression can occur for a fixed chemorepulsive strength.
细菌在形成多细胞菌落或生物膜时，可以通过多种复杂的机制进行模式形成。其中一种途径是朝向或远离自身分泌或外部使用的化学物质的定向运动或趋化性。在一些细菌中，自身产生的信号化学物质或自动诱导物本身可以作为趋化剂或化学抑制剂，从而调节菌落中细胞的定向运动。此外，细菌遵循一定的生长动力学，该动力学整合在菌落发育过程中。在这里，我们研究了细菌生长动态、细胞运动和自动趋化运动与自我分泌的扩散信号化学物质之间的相互作用，以研究空间模式形成。使用可动细菌的连续体模型，我们表明生长可以作为决定菌落时空动力学的关键调谐参数。在生长动力学的作用下，虽然自动诱导物的趋化性会导致相分离停止，但对于固定的化学排斥强度，模式转变和抑制也可能发生。
