LAUSR

Significance Culturing bacteria to produce desired chemicals has long been practiced in human history, and has recently being taken as a promising approach to sustainable energy when this process is driven by sunlight and fed by CO2 as the only carbon source. Among these chemical-producing microbes are anaerobic bacteria, inherently susceptible to O2 and reactive oxygen species that are inevitably generated on anodes. Here, we provide cytoprotection against such oxidative stress by wrapping bacteria with an artificial material, metal-organic frameworks (MOFs), which significantly enhances the lifetime of anaerobes in the presence of O2, and maintains the continuous production of acetic acid from CO2. The ultrathin nature of the MOF layer allows for cell reproduction without loss of this cytoprotective material. We report a strategy to uniformly wrap Morella thermoacetica bacteria with a metal-organic framework (MOF) monolayer of nanometer thickness for cytoprotection in artificial photosynthesis. The catalytic activity of the MOF enclosure toward decomposition of reactive oxygen species (ROS) reduces the death of strictly anaerobic bacteria by fivefold in the presence of 21% O2, and enables the cytoprotected bacteria to continuously produce acetate from CO2 fixation under oxidative stress. The high definition of the MOF–bacteria interface involving direct bonding between phosphate units on the cell surface and zirconium clusters on MOF monolayer, provides for enhancement of life throughout reproduction. The dynamic nature of the MOF wrapping allows for cell elongation and separation, including spontaneous covering of the newly grown cell surface. The open-metal sites on the zirconium clusters lead to 600 times more efficient ROS decomposition compared with zirconia nanoparticles.