Growth dynamics and mechanical properties of E. coli biofilms Biofilms are complex living materials that form as bacteria get embedded in a matrix of self produced protein and polysaccharide fibres. The formation of a network of extracellular biopolymer fibres contributes to the cohesion of the biofilm by promoting cell cell attachment and by mediating biofilm substrate interactions. This sessile mode of bacteria growth has been well studied by microbiologists to prevent the detrimental effects of biofilms in medical and industrial settings. Indeed biofilms are associated with increased antibiotic resistance in bacterial infections and they can also cause clogging of pipelines or promote bio corrosion. However biofilms also gained interest from biophysics due to their ability to form complex morphological patterns during growth. Recently the emerging field of engineered living materials investigates biofilm mechanical properties at multiple length scales and leverages the tools of synthetic biology to tune the functions of their constitutive biopolymers. This doctoral thesis aims at ...