Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications

The use of exoelectrogens in microbial fuel cells (MFCs) has given a wide berth to the addition of artificial electron shuttles/conduits as they have the molecular machinery to transfer the electrons exogenously to the electrode surface or to soluble or insoluble electron acceptors. Exoelectrogens t...

Full description

Bibliographic Details
Main Authors:	Kumar, Ravinder, Singh, Lakhveer, Zularisam, A. W.
Format:	Article
Language:	English
Published:	Elsevier 2016
Subjects:	TP Chemical technology
Online Access:	http://umpir.ump.edu.my/id/eprint/11699/ http://umpir.ump.edu.my/id/eprint/11699/ http://umpir.ump.edu.my/id/eprint/11699/ http://umpir.ump.edu.my/id/eprint/11699/7/ftech-2016-lakhveer-Exoelectrogens%20Recent%20advances.pdf

id	ump-11699
recordtype	eprints
spelling	ump-116992019-08-28T02:55:22Z http://umpir.ump.edu.my/id/eprint/11699/ Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications Kumar, Ravinder Singh, Lakhveer Zularisam, A. W. TP Chemical technology The use of exoelectrogens in microbial fuel cells (MFCs) has given a wide berth to the addition of artificial electron shuttles/conduits as they have the molecular machinery to transfer the electrons exogenously to the electrode surface or to soluble or insoluble electron acceptors. Exoelectrogens transfer the electrons either directly to the electrode surface (via c-Cyts or pili) and/or mediate them by secreting electron shuttles such as, flavins or pyocyanin. Such microorganisms form electroactive biofilms on the electrode surface. They produce cyclopropane fatty acids and exopolysaccahride matrix to modify surface charge, which also provides favorable anchoring points for the retention of c-type cytochromes (c-Cyts). The longer subunit of PilA plays a vital role in cell attachment in the case of a well-known exoelectrogen Geobacter sulfurreducens during biofilm formation. G. sulfurreducens relies on flavin molecules for mediated electron transfer (MET) during initial biofilm formation and on c-Cyts and pili for the direct electron transfer (DET) during the later phase of biofilm formation. A new protein, cbcl inner membrane multiheme c-Cyt has been revealed in G. sulfurreducens that participates in the electron transfer when electron acceptor with low reduction potential (below 0.1 V) is used in the MFCs. On the other hand, inner membrane c-type cytochrome ImcH is involved in the reduction of electron acceptors exhibiting the potential above 0.1 V. Shewanella oneidensis, another exoelectrogen expresses CheA-3 histidine protein kinase for chemotactic responses to electron acceptors. S. oneidensis do not produce pili and utilizes flavin-cytochrome complexes to regulate the electron transfer to the electrode surfaces. The inherent electron transfer rates can be increased in order to improve the MFC performance. Such strategies as the anode surface modification with nanoparticles, expression of the genes for flavin biosynthesis pathway in the exoelectrogens, and chemical treatment of the microbial membrane have shown to increase the current outputs in the MFCs. This article provides the latest information about the exoelectrogens and molecular drivers involved in extracellular electron transfer (EET) mechanisms, and also summarizes the important characteristics of electroactive biofilms. It also highlights the different approaches that have been employed to facilitate the EET mechanisms and some uncommon exoelectrogens used in the MFCs recently. Elsevier 2016-12-31 Article PeerReviewed application/pdf en http://umpir.ump.edu.my/id/eprint/11699/7/ftech-2016-lakhveer-Exoelectrogens%20Recent%20advances.pdf Kumar, Ravinder and Singh, Lakhveer and Zularisam, A. W. (2016) Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications. Renewable and Sustainable Energy Reviews, 56. pp. 1322-1336. ISSN 1364-0321 http://dx.doi.org/10.1016/j.rser.2015.12.029 DOI: 10.1016/j.rser.2015.12.029
repository_type	Digital Repository
institution_category	Local University
institution	Universiti Malaysia Pahang
building	UMP Institutional Repository
collection	Online Access
language	English
topic	TP Chemical technology
spellingShingle	TP Chemical technology Kumar, Ravinder Singh, Lakhveer Zularisam, A. W. Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications
description	The use of exoelectrogens in microbial fuel cells (MFCs) has given a wide berth to the addition of artificial electron shuttles/conduits as they have the molecular machinery to transfer the electrons exogenously to the electrode surface or to soluble or insoluble electron acceptors. Exoelectrogens transfer the electrons either directly to the electrode surface (via c-Cyts or pili) and/or mediate them by secreting electron shuttles such as, flavins or pyocyanin. Such microorganisms form electroactive biofilms on the electrode surface. They produce cyclopropane fatty acids and exopolysaccahride matrix to modify surface charge, which also provides favorable anchoring points for the retention of c-type cytochromes (c-Cyts). The longer subunit of PilA plays a vital role in cell attachment in the case of a well-known exoelectrogen Geobacter sulfurreducens during biofilm formation. G. sulfurreducens relies on flavin molecules for mediated electron transfer (MET) during initial biofilm formation and on c-Cyts and pili for the direct electron transfer (DET) during the later phase of biofilm formation. A new protein, cbcl inner membrane multiheme c-Cyt has been revealed in G. sulfurreducens that participates in the electron transfer when electron acceptor with low reduction potential (below 0.1 V) is used in the MFCs. On the other hand, inner membrane c-type cytochrome ImcH is involved in the reduction of electron acceptors exhibiting the potential above 0.1 V. Shewanella oneidensis, another exoelectrogen expresses CheA-3 histidine protein kinase for chemotactic responses to electron acceptors. S. oneidensis do not produce pili and utilizes flavin-cytochrome complexes to regulate the electron transfer to the electrode surfaces. The inherent electron transfer rates can be increased in order to improve the MFC performance. Such strategies as the anode surface modification with nanoparticles, expression of the genes for flavin biosynthesis pathway in the exoelectrogens, and chemical treatment of the microbial membrane have shown to increase the current outputs in the MFCs. This article provides the latest information about the exoelectrogens and molecular drivers involved in extracellular electron transfer (EET) mechanisms, and also summarizes the important characteristics of electroactive biofilms. It also highlights the different approaches that have been employed to facilitate the EET mechanisms and some uncommon exoelectrogens used in the MFCs recently.
format	Article
author	Kumar, Ravinder Singh, Lakhveer Zularisam, A. W.
author_facet	Kumar, Ravinder Singh, Lakhveer Zularisam, A. W.
author_sort	Kumar, Ravinder
title	Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications
title_short	Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications
title_full	Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications
title_fullStr	Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications
title_full_unstemmed	Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications
title_sort	exoelectrogens: recent advances in molecular drivers involved in extracellular electron transfer and strategies used to improve it for microbial fuel cell applications
publisher	Elsevier
publishDate	2016
url	http://umpir.ump.edu.my/id/eprint/11699/ http://umpir.ump.edu.my/id/eprint/11699/ http://umpir.ump.edu.my/id/eprint/11699/ http://umpir.ump.edu.my/id/eprint/11699/7/ftech-2016-lakhveer-Exoelectrogens%20Recent%20advances.pdf
first_indexed	2023-09-18T22:12:38Z
last_indexed	2023-09-18T22:12:38Z
_version_	1777415129426558976

Exoelectrogens: Recent Advances in Molecular Drivers Involved in Extracellular Electron Transfer and Strategies used to Improve it for Microbial Fuel Cell Applications

Similar Items