Towards unravelling the mechanism and function of exoelectrogenesis in cyanobacteria
type: CreativeWork
description: Photosynthetic microorganisms, including algae and cyanobacteria, are able to export electrons derived from the photosynthetic electPhotosynthetic microorganisms, including algae and cyanobacteria, are able to export electrons derived from the photosynthetic electron transport chain to the cell exterior, in a phenomenon known as exoelectrogenesis. This phenomenon has implications for an emerging field of biotechnology which seeks to employ photosynthetic biocatalysts to produce solar electricity, chemicals and fuels (bioelectrochemical systems). However, both the underlying mechanism by which exoelectrogenesis occurs and the function that exoelectrogenesis plays in photomicrobial communities are poorly understood. This gap in understanding represents a barrier to the intelligent design of biophotoelectrochemical systems, hindering their development into a practical technology. At a fundamental level this also represents a gap in the understanding of the biochemical mechanisms of photosynthesis, one of the most important and widespread biochemical pathways in life. The cyanobacteria *Synechocystis* sp. PCC 6803 is used throughout this work as a model organism for the study of photosynthesis and exoelectrogenesis. The research presented in this thesis aims to deepen understanding of the mechanism and function of exoelectrogenesis in cyanobacteria by generating and employing a workflow for identifying the endogenous redox mediator, developing a platform for *in operando* electrochemistry and microscopy, and using it to study the dynamic spatial variations in biofilm behaviour during exoelectrogenesis. First, the question of the mechanism of exoelectrogenesis is examined. Exoelectrogenesis is known to occur in cyanobacteria through the secretion of a small, soluble redox mediator, with the identity of this mediator having remained unknown for many years. Recently, a proposal for the identity of this mediator was put forward: this work begins by critically assessing the …
abstract: Photosynthetic microorganisms, including algae and cyanobacteria, are able to export electrons derived from the photosynthetic electPhotosynthetic microorganisms, including algae and cyanobacteria, are able to export electrons derived from the photosynthetic electron transport chain to the cell exterior, in a phenomenon known as exoelectrogenesis. This phenomenon has implications for an emerging field of biotechnology which seeks to employ photosynthetic biocatalysts to produce solar electricity, chemicals and fuels (bioelectrochemical systems). However, both the underlying mechanism by which exoelectrogenesis occurs and the function that exoelectrogenesis plays in photomicrobial communities are poorly understood. This gap in understanding represents a barrier to the intelligent design of biophotoelectrochemical systems, hindering their development into a practical technology. At a fundamental level this also represents a gap in the understanding of the biochemical mechanisms of photosynthesis, one of the most important and widespread biochemical pathways in life. The cyanobacteria *Synechocystis* sp. PCC 6803 is used throughout this work as a model organism for the study of photosynthesis and exoelectrogenesis. The research presented in this thesis aims to deepen understanding of the mechanism and function of exoelectrogenesis in cyanobacteria by generating and employing a workflow for identifying the endogenous redox mediator, developing a platform for *in operando* electrochemistry and microscopy, and using it to study the dynamic spatial variations in biofilm behaviour during exoelectrogenesis. First, the question of the mechanism of exoelectrogenesis is examined. Exoelectrogenesis is known to occur in cyanobacteria through the secretion of a small, soluble redox mediator, with the identity of this mediator having remained unknown for many years. Recently, a proposal for the identity of this mediator was put forward: this work begins by critically assessing the …
author: Wroe, Evan
language: eng
keywords: Bacterial Membrane Potential, Bioelectrochemistry, Cyanobacteria, Extracellular Electron Transfer, Microbial Electrochemistry, Photosynthesis
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/73cfbe9d-09c0-4eb1-8452-fcec9ab13db0/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2024-01-25
date modified: 2026-07-22T22:24:16Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.109481