Increased Nitrogenase Activity in Solar-Driven Biohybrids Containing Non-photosynthetic Bacteria and Conducting Polymers

Angew Chem Int Ed Engl. 2023 Jul 24;62(30):e202303877. doi: 10.1002/anie.202303877. Epub 2023 Jun 15.

Abstract

A conductive polymer-based photosynthetic biohybrid is constructed to enhance biological nitrogen fixation by increasing nitrogenase activity in the non-photosynthetic bacterium Azotobacter Chroococcum (A. Chroococcum). The light-harvesting cationic poly(fluorene-alt-phenylene) (PFP) electrostatically binds to the surface of the bacteria and possesses satisfactory conductivity to facilitate electron transfer to the bacterium, promoting the nitrogen fixation pathway through redox proteins on the surface of the bacteria when under illumination. Therefore, the nitrogenase activity, hydrogen, NH4 + -N and L-amino acids production are increased by 260 %, 37 %, 44 %, and 47 %, respectively. The expression levels of nifD and nifK encoding molybdenum-iron (MoFe) protein and relevant nitrogen-fixing proteins are up-regulated. These photoactive conductive polymer-bacteria biohybrids provide a new method for improving the biological nitrogen fixation capability of non-photosynthetic nitrogen-fixing bacteria.

Keywords: Azotobacter Chroococcum; Biohybrids; Conductive Polymers; Nitrogenase; Photoinduced Electrons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Iron / metabolism
  • Molybdoferredoxin / metabolism
  • Nitrogen Fixation*
  • Nitrogenase* / metabolism
  • Oxidation-Reduction

Substances

  • Nitrogenase
  • Molybdoferredoxin
  • Iron