Abstract

Various bacterial strains exhibit colonial branching patterns during growth on thin poor substrates. The growth can be either diffusion-limited or kinetic-limited, according to the imposed growth conditions. We present experimental observations of patterns exhibited by the bacterial strains Paenibacillus dendritiformis and Paenibacillus vortex. All manners of branching patterns are observed, the three main being: 1) basic branching; 2)chiral branching; 3) vortex branching. We show that the following biological features can explain the spectrum of observed patterns: 1. Formation of a lubricating fluid. 2. Food chemotaxis. 3. Attractive and repulsive chemotaxis signaling. 4. Flagella handedness. 5. Transition into pre-spore state. In the theoretical studies we employ knowledge drawn from branching patterning in non-living systems and the mathematical properties of reaction-diffusion models and atomistic models. The above can be used not just to describe existing biological und...

Citations