Article
Biotechnology & Applied Microbiology
Fernanda Jimenez Otero, Grayson L. Chadwick, Matthew D. Yates, Rebecca L. Mickol, Scott H. Saunders, Sarah M. Glaven, Jeffrey A. Gralnick, Dianne K. Newman, Leonard M. Tender, Victoria J. Orphan, Daniel R. Bond
Summary: A study on a strain of Geobacter sulfurreducens lacking four of five outer membrane cytochrome complexes found that its biofilm growth is faster and produces greater current density. This increased performance is attributed to denser cell packing close to the electrode and higher metabolic rates per cell, as indicated by increased rates of N-15 incorporation. Additionally, the engineered strain shows a higher rate of electron transfer through biofilms compared to the wild type, suggesting a streamlined electron transfer pathway for enhanced current production.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Engineering, Environmental
Xuejun Yan, Qing Du, Quanhua Mu, Lili Tian, Yuxuan Wan, Chengmei Liao, Lean Zhou, Yuqing Yan, Nan Li, Bruce E. Logan, Xin Wang
Summary: The study observed a succession between two closely related Geobacter species in MFC biofilms, with G. spp. predominant near the electrode and aerobes abundant in the outer layer. Removing the outer aerobes led to a transition from G. sulfurreducens to G. anodireducens. The competition between the two species was influenced by cell size, extracellular polymeric substances, and cell numbers.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Microbiology
Jie Jiang, Pengchen He, Ying Luo, Zhaofeng Peng, Yongguang Jiang, Yidan Hu, Lei Qi, Xiuzhu Dong, Yiran Dong, Liang Shi
Summary: The pilA-N, omcE, omcS, omcT, and omcZ genes of Geobacter sulfurreducens have different roles in extracellular electron transfer (EET), enabling efficient EET reactions with substrates of different properties.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Microbiology
Angel Andrade, Alberto Hernandez-Eligio, Ana Lilia Tirado, Leticia Vega-Alvarado, Maricela Olvera, Enrique Morett, Katy Juarez
Summary: Integration host factor (IHF) is a small heterodimeric protein involved in multiple DNA regulatory processes in bacteria, mainly linked with the regulation of RpoN-dependent promoters. In certain bacteria, the genes encoding IHF subunits may be duplicated, yet their functionality remains unknown.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Maksym Karamash, Michael Stumpe, Jorn Dengjel, Carlos A. Salgueiro, Bernd Giese, Katharina M. Fromm
Summary: This study investigated the influence of metal salts and multiheme c-cytochromes on electron flux during the respiration process of Geobacter sulfurreducens. The reduction kinetics of different metal salts were measured, and it was found that the reduction rates were similar for all salts and followed zero-order kinetics. C-cytochromes played a role in stabilizing respiration rates by varying their redox states, and increasing Fe2+/heme levels enhanced electron flux and respiration flexibility. The findings parallel the electrochemical results of G. sulfurreducens biofilms and can contribute to the optimization of bioelectrochemical devices.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Environmental Sciences
Zheng Zhuang, Guiqin Yang, Li Zhuang
Summary: The study investigated the role of exopolysaccharides in electroactive biofilms by constructing an exopolysaccharides-deficient Geobacter sulfurreducens-based BES. The findings demonstrated the essential role of exopolysaccharides in extracellular electron transfer (EET) and early biofilm formation, with pili playing a compensatory role in biofilm formation. The mutant biofilm had lower cell viability, thinner biofilm, and decreased electrochemical activity compared to the wild-type biofilm.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Biotechnology & Applied Microbiology
Roland Berthomieu, Maria Fernanda Perez-Bernal, Gaelle Santa-Catalina, Elie Desmond-Le Quemener, Nicolas Bernet, Eric Trably
Summary: The study revealed the interaction mechanism between the electroactive bacterium Geobacter sulfurreducens and Clostridium pasteurianum, with Geobacter sulfurreducens potentially modifying the metabolic pathway of Clostridium pasteurianum through the production of cofactor molecules, and entering Clostridium pasteurianum with its electrons, possibly reinforcing the metabolic shift in Clostridium pasteurianum.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Sergio Martinez-Bahena, Alberto Hernandez-Eligio, Guillermo Antonio Huerta-Miranda, Dulce Castrejon-Lopez, Margarita Miranda-Hernandez, Katy Juarez
Summary: Type IV pili and >100c-type cytochromes in Geobacter sulfurreducens play a crucial role in extracellular electron transfer (EET) towards metal oxides and electrodes. A study reveals that the GSU1771 gene is involved in regulating EET and the formation of electroactive biofilms. The deletion of this gene enhances the reduction of Fe(III) oxides and leads to thicker biofilms with higher electrical current production.
BIOELECTROCHEMISTRY
(2022)
Article
Biotechnology & Applied Microbiology
Ayako Kai, Takahiro Tokuishi, Takashi Fujikawa, Yoshihiro Kawano, Toshiyuki Ueki, Miyuki Nagamine, Yoichi Sakakibara, Masahito Suiko, Kengo Inoue
Summary: The c-type cytochrome OmcZ in Geobacter sulfurreducens is essential for optimal current production in microbial fuel cells. A subtilisin-like serine protease called OzpA plays a key role in cleaving OmcZ and generating the mature form OmcZ(S), which is crucial for extracellular electron transfer to electrodes. This proteolytic maturation of OmcZ is a unique regulation mechanism in G. sulfurreducens, providing new insights for efficient energy conversion from chemical energy to electricity.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Multidisciplinary Sciences
Yonggang Yang, Zegao Wang, Cuifen Gan, Lasse Hyldgaard Klausen, Robin Bonne, Guannan Kong, Dizhou Luo, Mathijs Meert, Chunjie Zhu, Guoping Sun, Jun Guo, Yuxin Ma, Jesper Tataru Bjerg, Jean Manca, Meiying Xu, Lars Peter Nielsen, Mingdong Dong
Summary: Long-distance extracellular electron transfer has been observed in Gram-negative bacteria and now also in a filamentous, unicellular Gram-positive bacterium. The filamentous bacterium Lysinibacillus varians GY32 is capable of bidirectional extracellular electron transfer, forming centimetre-range conductive cellular networks with 1mm-long cells and conductive appendages. Our results demonstrate that Gram-positive bacteria can also participate in long-distance electron transfer processes.
NATURE COMMUNICATIONS
(2021)
Editorial Material
Biochemistry & Molecular Biology
Matthew J. Guberman-Pfeffer, Nikhil S. Malvankar
Summary: Living cells need to dispose of leftover electrons during metabolism, and soil microbes like Geobacter sulfurreducens have evolved a method of anaerobic respiration using nanowires for extracellular electron transfer. Recent studies have revealed that the nanowires are composed of multiheme cytochromes, which may open up possibilities for optimizing bioenergetic machinery for various applications.
BIOCHEMICAL JOURNAL
(2021)
Article
Biotechnology & Applied Microbiology
Zhigao Wang, Yidan Hu, Yiran Dong, Liang Shi, Yongguang Jiang
Summary: This study demonstrates for the first time that overexpression of nanowire proteins can increase the biomass and electroactivity of anode-attached microbial biofilms, and enhance the electrical outputs of microbial fuel cells.
MICROBIAL BIOTECHNOLOGY
(2023)
Review
Chemistry, Multidisciplinary
Jiyao Li, Hexing Han, Yanhong Chang, Bin Wang
Summary: This review provides a comprehensive summary of the material-microorganism interface in microbial hybrid electrocatalysis systems. The electron transfer at the interfaces between microorganisms and materials is a critical issue that affects system efficiency. The strategies for building efficient microorganism and material interfaces, including material design, modification, and bacterial engineering, are discussed. Understanding the interface between electrode/active materials and microorganisms could help advance the development of material-microorganism hybrid electrocatalysis systems.
Article
Biotechnology & Applied Microbiology
Hanna Marianne Fruehauf, Markus Stoeckl, Dirk Holtmann
Summary: A quantitative method was developed to measure biofilm thickness using confocal laser scanning microscopy and R programming language. The method was applied in microbial fuel cell experiments and showed a positive correlation between biofilm thickness and current density, but no direct link to the applied potential.
ENGINEERING IN LIFE SCIENCES
(2022)
Review
Biotechnology & Applied Microbiology
Edina M. M. Klein, Melanie T. T. Knoll, Johannes Gescher
Summary: Microbial electrochemical systems (MESs) are a versatile platform technology focused on power or energy production, often combined with substrate conversion and value-added compound production. This review provides a brief summary of the terminology and essential biological background of MES technology. Recent research on improvements at the biofilm-electrode interface is discussed, comparing biotic and abiotic approaches. The review concludes with future directions for increasing process efficiency in MES technology.
MICROBIAL BIOTECHNOLOGY
(2023)
