Reversing Electron Transfer Chain for Light-Driven Hydrogen Production in Biotic–Abiotic Hybrid Systems

Abstract

The biotic–abiotic photosynthetic system integrating inorganic light absorbers with whole-cell biocatalysts innovates the way for sustainable solar-driven chemical transformation. Fundamentally, the electron transfer at the biotic–abiotic interface, which may induce biological response to photoexcited electron stimuli, plays an essential role in solar energy conversion. Herein, we selected an electro-active bacterium Shewanella oneidensis MR-1 as a model, which constitutes a hybrid photosynthetic system with a self-assembled CdS semiconductor, to demonstrate unique biotic–abiotic interfacial behavior. The photoexcited electrons from CdS nanoparticles can reverse the extracellular electron transfer (EET) chain within S. oneidensis MR-1, realizing the activation of a bacterial catalytic network with light illumination. As compared with bare S. oneidensis MR-1, a significant upregulation of hydrogen yield (711-fold), ATP, and reducing equivalent (NADH/NAD+) was achieved in the S. oneidensis MR-1-CdS under visible light. This work sheds light on the fundamental mechanism and provides design guidelines for biotic–abiotic photosynthetic systems.

Engineered Living Materials For Sustainability

“…443,444 Given this, Luo et al and Han et al exploited S. oneidensis MR-1 to uptake CuInS2/ZnS QDs or immobilize CdS nanoparticles on the cell membrane to fabricate bioinorganic hybrids for hydrogen generation. 443,445 Finally, Wang et al explored an approach to anchor the QDs on genetically modified E. coli biofilms to decrease the detrimental effects of semiconductors on living systems (Figure 28f,g). 438 The incorporation of nanoparticles endowed the engineered biofilms with light-triggered H 2 generation capacity (Figure 28h).…”

Prospective Roles of Scanning Photoelectrochemical Microscopy in Microbial Hybrid Photosynthesis†

“…In addition, these materials enhance the electron transfer efficiency of microbial hybrid systems. For example, when photosensitizers are internalized into microbial cells, photoexcited electrons are transferred directly from photosensitizers to the Wood–Ljungdahl pathway for acetic acid production from CO 2 , [ 6 ] or to the MoFe protein for ammonia production from N 2 . [ 7 ] Efforts to discover and develop efficient and affordable catalysts to selectively generate a variety of complex carbon‐ and nitrogen‐based compounds are ongoing.…”

Endowing cells with unnatural photocatalytic ability for sustainable chemicals production by bionic minerals-triggering

“…12,13 In addition, a CdS nanophotosensitizer precipitated on the surface of S. oneidensis MR-1 can also promote the solar-to-hydrogen production of hydrogenases inside bacteria. 14…”