Frequency dependent growth of bacteria in living materials

Abstract

The fusion of living bacteria and man-made materials represents a new frontier in medical and biosynthetic technology. However, the principles of bacterial signal processing inside three dimensional and fluctuating environments of synthetic materials remain elusive. Here, we study bacterial growth in a three-dimensional hydrogel. We find that bacteria expressing an antibiotic resistance module can take advantage of ambient kinetic disturbances to improve growth while encapsulated. We show that these changes in bacterial growth are specific to disturbance frequency and hydrogel density. This remarkable specificity is consistent with stochastic resonance theory, which we leverage to explain how bacteria can integrate spatial and temporal information to control growth. This research provides a quantitative foundation for the control of living materials and a systematic framework towards understanding bacterial information processing in three-dimensional environments.