However, their parameterization of the bending modulus is not acceptable because it leads to an unreasonably large (0.5 metre) persistence length for a bacterial trichome.
The literature seems to indicate a low value of the bending modulus (alpha) that corresponds to a persistence length of 500 microns. The authors instead use alpha = 2 × 10−21 Nm2, which is 1000× larger. With this value, the persistence length = alpha/(kbT) = 0.5 metres. This seems orders of magnitude too large, especially in the face of the results of Boal and Ng [44]. The authors need to be in a physical regime of parameter space in order to confront their results with observed patterns. Otherwise, they are just fitting a non-linear phenomenon with a (potentially inappropriate) non-linear model— in this case agreement does not provide firm insight into the physical system.