Artificially sporulated Escherichia coli cells as a robust cell factory for interfacial biocatalysis

Whole-cell biocatalysis is of interest for the efficient production of a range of products but cell stability can be an issue. Here, the authors turn recombinant enzyme-producing E. coli into artificial spores to add protection from UV radiation, heating, and organic solvents by coating the cells with polydopamine to create robust cell factories. The natural bacterial spores have inspired the development of artificial spores, through coating cells with protective materials, for durable whole-cell catalysis. Despite attractiveness, artificial spores developed to date are generally limited to a few microorganisms with their natural endogenous enzymes, and they have never been explored as a generic platform for widespread synthesis. Here, we report a general approach to designing artificial spores based on Escherichia coli cells with recombinant enzymes. The artificial spores are simply prepared by coating cells with polydopamine, which can withstand UV radiation, heating and organic solvents. Additionally, the protective coating enables living cells to stabilize aqueous-organic emulsions for efficient interfacial biocatalysis ranging from single reactions to multienzyme cascades. Furthermore, the interfacial system can be easily expanded to chemoenzymatic synthesis by combining artificial spores with metal catalysts. Therefore, this artificial-spore-based platform technology is envisioned to lay the foundation for next-generation cell factory engineering.

Automated summary

The authors developed a general approach to designing artificial spores based on Escherichia coli cells with recombinant enzymes. These artificial spores were prepared by coating cells with polydopamine, providing protection from UV radiation, heating, and organic solvents. The protective coating enabled the cells to stabilize aqueous-organic emulsions for efficient interfacial biocatalysis and could be expanded to chemoenzymatic synthesis by combining artificial spores with metal catalysts.