Response of bacterial colonies to imposed anisotropy

Abstract

We present theoretical and experimental studies of bacterial growth patterns in the presence of imposed anisotropy. The role of chemotactic signaling in the cooperative response of the bacteria is demonstrated. In the presence of sixfold symmetry, patterns with a tantalizing similarity to those of snowflakes are formed. Transitions from concave to convex shaped envelope as a function of peptone level are observed in the presence of fourfold lattice anisotropy. \textcopyright{} 1996 The American Physical Society.