The intersection of materials science and synthetic biology enables the production of engineered living materials (ELMs) with functionalities such as the ability to self-repair, autonomously control morphology, and sense-and-respond to environmental stimuli. The interface between living cells and synthetic polymer scaffolds is a crucial design element of ELMs that requires further research to make these materials industrially relevant. Herein, we report the development of two unique conjugation strategies that enable covalent crosslinking of B. subtilis within a PEGDA hydrogel. B. subtilis surface chemistry is exploited to conjugate polymerizable “handles” that enable cellular crosslinking via free radical polymerization.