Solar-Driven Producing of Value-Added Chemicals with Organic Semiconductor-Bacteria Biohybrid System

Abstract

Photosynthetic biohybrid systems exhibit promising performance in biosynthesis; however, these systems can only produce a single metabolite and cannot further transform carbon sources into highly valuable chemical production. Herein, a photosynthetic biohybrid system integrating biological and chemical cascade synthesis was developed for solar-driven conversion of glucose to value-added chemicals. A new ternary cooperative biohybrid system, namely bacterial factory, was constructed by self-assembling of enzyme-modified light-harvesting donor-acceptor conjugated polymer nanoparticles (D-A CPNs) and genetically engineered Escherichia coli (E. coli). The D-A CPNs coating on E. coli could effectively generate electrons under light irradiation, which were transferred into E. coli to promote the 37% increment of threonine production by increasing the ratio of nicotinamide adenine dinucleotide phosphate (NADPH). Subsequently, the metabolized threonine was catalyzed by threonine deaminase covalently linking with D-A CPNs to obtain 2-oxobutyrate, which is an important precursor of drugs and chemicals. The 2-oxobutyrate yield under light irradiation is increased by 58% in comparison to that in dark. This work provides a new organic semiconductor-microorganism photosynthetic biohybrid system for biological and chemical cascade synthesis of highly valuable chemicals by taking advantage of renewable carbon sources and solar energy.

Photodriven Chemical Synthesis by Whole-Cell-Based Biohybrid Systems: From System Construction to Mechanism Study

“…On the other hand, besides the techniques mentioned above, more robust and valid techniques are expected to be utilized in the charge transfer mechanism study of the PBSs to get more comprehensive understanding of the fundamental interaction between the biotic and abiotic interface. Conventional electrochemical methods, e.g., cyclic voltammetry ,,,, and differential pulse voltammetry, , are commonly used to study the electron transmembrane transport, which can characterize the redox process of membrane-bound proteins in various media during electron transfer and assess their electron transfer capacities. Microscopies, including atomic force microscopy, confocal laser scanning microscope, ,, structure illumination microscopy, cryo-electro tomography, and fluorescence microscopy, ,, realize visualization of membrane-bound protein distribution on the inner cell membrane, periplasm, outer cell membrane, and nanomaterials in a more intuitive way.…”

“…Conventional electrochemical methods, e.g., cyclic voltammetry ,,,, and differential pulse voltammetry, , are commonly used to study the electron transmembrane transport, which can characterize the redox process of membrane-bound proteins in various media during electron transfer and assess their electron transfer capacities. Microscopies, including atomic force microscopy, confocal laser scanning microscope, ,, structure illumination microscopy, cryo-electro tomography, and fluorescence microscopy, ,, realize visualization of membrane-bound protein distribution on the inner cell membrane, periplasm, outer cell membrane, and nanomaterials in a more intuitive way. Spectroscopy enables an in-depth investigation of electron transfer processes.…”

“…26 Additionally, CPNs can be easily coupled with biological agents like enzymes, taking advantage of their large surface area and active modification groups. 95 Yu et al 96 designed well-structured donor−acceptor CPNs modified with threonine deaminase (D−A CPNs@ Enzyme), which were then incubated with genetically engineered E. coli to form a biohybrid. The photoelectrons produced by D−A CPNs@Enzyme were transferred to E. coli by membrane-bound proteins, accelerating the accumulation of intracellular NADPH so as to improve threonine production from glucose, which was 37% higher than that of pure E. coli.…”

“…Additionally, CPNs can be easily coupled with biological agents like enzymes, taking advantage of their large surface area and active modification groups . Yu et al designed well-structured donor–acceptor CPNs modified with threonine deaminase (D–A CPNs@Enzyme), which were then incubated with genetically engineered E. coli to form a biohybrid.…”

Photosynthetic Polymer Dots–Bacteria Biohybrid System Based on Transmembrane Electron Transport for Fixing CO2 into Poly-3-hydroxybutyrate

“…However, the optical properties of inorganic semiconductors are difficult to control, and also these materials are often toxic to bacteria. Conjugated polymer dots (Pdots) have a wide development in the field of energy conversion − and biological applications − because of their structural versatility, adjustable optical gap, easy modification, and p-conjugated structure, which facilitates electron tunneling . Biocompatible Pdots are therefore considered good photosensitizer candidates for photosynthetic biohybrid systems .…”