Felix Barber

Abstract Rod-shaped bacteria such as Bacillus subtilis achieve their shape by using Rod complexes to synthesize anisotropic peptidoglycan and by limiting isotropic peptidoglycan synthesis by PBP1. Wall teichoic acids are also required for rod shape, but their role is unclear. Here we use single-cell microfluidics and microscopy to show that wall teichoic acids promote rod shape by preventing the formation of nanoscopic pores in the B. subtilis cell wall.

Because finger-trap deformation corresponds to constriction of cell width upon elongation, our results raised the possibility that this behavior was required to avoid runaway widening during cell growth. To explore this hypothesis theoretically, we constructed a simple physical model for the irreversible mechanical expansion of a linear elastic, layered cell wall that accounts for dynamics of cell length and width (Figure 3A).