Concentrating and preserving living microbes in thin (<100μm), adhesive nanoporous coatings may be useful for engineering high intensity biocatalysts for environmental and energy applications.  Biocatalytic coatings facilitate engineering microchannel or membrane bioreactors for multi-phase biocatalysis for CO_x sequestration and biological conversion of waste organics to fuels (hydrogen, methanol, ethanol) and chemicals.  Several model systems and methods for coating self-assembling polymer particles and living microbes are being studied.  The goal is to understand how to  engineer polymer-cell interactions and coating microstructure.  Coatings may be particularly useful for illumination of concentrated photosynthetic microbes. Anoxic coatings of nitrogen-limited Rhodospeudomonas palustris and sulfur-limited Chlamydomonas reinhardtii are model systems we study for optical and light scattering properties using hydrogen production for reactivity.  Single and multi-layer latex coatings are investigated to optimize light adsorption, and understand light scattering in relation to the rate of hydrogen production per illuminated surface area.  Algal coatings and coatings of non-photosynthetic anaerobic bacteria could also be useful for gas-phase carbon sequestration.  A key characteristic of these systems is preservation of microbial activity and viability simultaneous with formation of nanopores during polymer particle coalescence (film formation).  Latex coating emulsions are free of biocides and toxic polymer synthesis monomers.  Even with non-toxic latex emulsions, drying rate and conditions can kill some microbes as a result of desiccation and osmotic stress. The response of C. reinhardtii during drying is being investigated using cellular stress responses to engineer polymer emulsion and coating methods for adhesive algal coatings with high viability and reactivity.