Nanoporous, adhesive latex coatings containing ~50% (v/v) of the nitrogen-fixing purple non-sulfur bacterium Rhodopseudomonas palustris preserve viability at ambient temperature and, in the absence of atmospheric nitrogen, generate H₂ gas when illuminated.  These photo-reactive coatings have a surface to volume ratio >100-fold larger than any other photobioreactors and may be useful for large-scale anoxic production of hydrogen from waste organic acids and sunlight.  Non-toxic low T_g latex emulsions containing carbohydrate porogens and Rps. palustris can be cast into thin (<100 μm thick) coatings capable of forming nanopores surrounding the cells during film formation and coat drying. The porogens form nanopores by reducing capillary pressure and arresting polymer particle coalescence.  Porogens are vitrified in the pore space during drying which preserves the viability of the partially desiccated latex-entrapped microbes. Coating reactivity is a function of cell density, thickness, nanoporosity, optical properties, nitrogenase activity and photopigment content.  Coatings can be stored at    -80˚C without significant loss of activity; coating microstructure affects hydrogen evolution rate.  Hydrated coating microstructure is visualized using cryogenic field emission scanning electron microscopy (cryo-FESEM).  6.25 cm² coatings periodically supplied with acetate under an argon atmosphere at 30˚C with continuous illumination generate hydrogen at a constant rate for over 3,000 hours indicating that cell viability and nitrogenase enzyme activity are stable for months.  The optical properties of Rps. palustris coatings are being investigated by experimental and light scattering modeling approaches.  Optimization of light adsorption per meter² is investigated using combinations of photopigment mutants in multilayer coatings.  A 1/100 meter² model coating bioreactor has been constructed to test continuous-flow system design.  A similar approach is being used to develop coatings to preserve the viability of Chlamydomonas reinhardtii which uses hydrogenase to generate H₂.  Optimized photo-reactive “microbial latex paints” may be useful for inexpensive large-surface area photo adsorbers for generation of H₂ from wastes for use in fuel cells to generate electricity.  This coating technology could also be used to produce H₂ for sequestration of point-source carbon dioxide gas by hydrogenation to methanol generating a useful liquid fuel and chemical intermediate.