Designing a periplasmic photosynthetic biohybrid system for succinate and electric energy production

Abstract

The emergence of photosynthetic biohybrid systems provides an environmentally friendly and sustainable approach to produce fuels and chemicals in microbial cell factories. However, the low efficiency of electron transfer between semiconductors and microorganisms hinders production efficiency. In this study, a periplasmic photosynthetic biohybrid system (PPB) was developed in E. coli through biological self-synthesis and optimized through engineering the periplasmic cytochrome network and cell membrane fluidity. The PPB significantly increased succinate production to a titer of 121.8 g/L in a 5 L fermenter by improving the reducing equivalents utilization. Additionally, the PPB was employed to establish a glucose-utilizing microbial consortium that exhibited robust performance, producing consistent electric energy output for a minimum of 17 days and achieving a maximum power density of 225.3 mW/m2. These findings demonstrate the capability of the PPB to enhance chemical production and generate electric energy from renewable carbon sources, thereby driving advances in green chemistry and promoting environmentally friendly industrial processes.