Article
Microbiology
Elena Yunda, Mareike Gutensohn, Madeleine Ramstedt, Erik Bjorn
Summary: This study reports the formation of methylmercury (MeHg) in biofilms of the iron-reducing bacterium Geobacter sulfurreducens. The biofilms cultivated in medium with vitamins for 3 days had the highest surface coverage and abundant extracellular matrix. The results demonstrate that G. sulfurreducens biofilms have a high Hg(II) methylation capacity and that Hg(II) transfer to the biofilm is the rate-limiting step for MeHg formation in this system.
FRONTIERS IN MICROBIOLOGY
(2023)
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
Biotechnology & Applied Microbiology
Lewis Grozinger, Elizabeth Heidrich, Angel Goni-Moreno
Summary: Synthetic biology utilizes molecular biology to create genetic circuits that can perform computations. These circuits process inputs and produce outputs based on predefined rules encoded in genetic parts. However, recent advancements in the field have shifted towards using mechanisms beyond genetic parts for engineering biological circuits. This study explores the use of electrogenic processes for circuit design and presents a model of a hybrid genetic and electrogenetic toggle switch operating in a biofilm attached to an electrode. Computational simulations were conducted to identify circuit design principles that result in bistability, providing a foundation for the rational design and implementation of hybrid devices that can be controlled genetically and electronically.
MICROBIAL BIOTECHNOLOGY
(2023)
Article
Engineering, Environmental
Xiaofeng Yi, Shenhua Huang, Lu Chang, Zhaoshou Wang, Yuanpeng Wang
Summary: The study investigated As(V) immobilization and redistribution processes during ferrihydrite reduction mediated by Geobacter sulfurreducens. The results showed that As(V) was redistributed on different minerals and EPS induced by G. sulfurreducens, with the addition of TiO2 nanoparticles delaying rather than promoting the entire process. Changes in aqueous arsenic and iron concentrations were found to be closely related to the formation time of secondary minerals.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
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
Engineering, Environmental
Tao Wang, Gefu Zhu, Bin Kuang, Jianbo Jia, Changyu Liu, Guanjing Cai, Chunxing Li
Summary: The co-culture of G. sulfurreducens and S. fumaroxidans in bioelectrochemical cells achieved more efficient propionate degradation compared to the control group. Carbon resource concentration and pH were both significantly correlated with propionate degradation. G. sulfurreducens strengthened the consumption of H-2 and acetate via direct interspecific electron transfer in propionate degradation.
Article
Electrochemistry
Xiaojia He, Grayson Chadwick, Fernanda Jimenez Otero, Victoria Orphan, Christof Meile
Summary: Utilizing a spatially resolved numerical model, this study reveals that the distribution of electric potential and pH control cellular metabolism in G. sulfurreducens biofilms, supporting the presence of two activity modes. The model provides insights into fundamental mechanisms of electron transfer at Micron-scale in conductive biofilms, which can inform the design of MFCs to maximize current production.
Article
Multidisciplinary Sciences
Pierre Belleville, Gerard Merlin, Julien Ramousse, Jonathan Deseure
Summary: This study investigates the limitation of activity distribution in electroactive biofilm using a numerical model. The competition between acetate diffusion and electronic conduction is found to be the major factor influencing metabolic activity distribution. The properties of inactive biomass fraction can alter the local biomass distribution, with increased density reducing acetate diffusion and enhancing outer layer biomass activity. High conductivity of the inactive fraction promotes outer layer biomass activity and current production.
SCIENTIFIC REPORTS
(2022)
Article
Biotechnology & Applied Microbiology
Veerraghavulu Sapireddy, Krishna P. Katuri, Ali Muhammad, Pascal E. Saikaly
Summary: The functional stability of microbial electrolysis cell (MEC) treating wastewater relies on maintaining the functional redundancy of efficient electroactive bacteria (EAB) on the anode biofilm. Investigating whether efficient EAB competing for the same resources co-exist at the anode biofilm is crucial for the successful application of MEC for wastewater treatment. The study compared the electrochemical and kinetic properties of two efficient acetoclastic EAB, Geobacter sulfurreducens (GS) and Desulfuromonas acetexigens (DA), suggesting that DA outcompetes GS for anode-dependent growth in acetate-fed co-culture MECs, while both EAB co-exist in wastewater-fed co-culture MECs despite the advantage of DA based on kinetic parameters alone.
NPJ BIOFILMS AND MICROBIOMES
(2021)
Article
Biotechnology & Applied Microbiology
Mon Oo Yee, Lars D. M. Ottosen, Amelia-Elena Rotaru
Summary: Improving methane production through electrical current application to anaerobic digesters has garnered interest, but this study shows that electrochemical stimulation has an overall detrimental effect on a direct interspecies electron transfer (DIET) consortium. The presence of an alternative electron donor inhibits efficient electron retrieval by the methanogen from Geobacter and induces catabolic repression of oxidative metabolism in Geobacter.
MICROBIAL BIOTECHNOLOGY
(2023)
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
Biochemistry & Molecular Biology
Zhenhua Shi, Zhen Yu, Wanqiu Chen
Summary: This study using single-molecule real-time DNA sequencing uncovered the presence of m4C modification in bacterial genomes, and demonstrated its distribution pattern following a power function. The biochemical reaction of m4C modification was found to have a distance effect, with different patterns observed in the positive, negative, and double strands of genomic DNA sequences.
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Peter J. Dahl, Sophia M. Yi, Yangqi Gu, Atanu Acharya, Catharine Shipps, Jens Neu, J. Patrick O'Brien, Uriel N. Morzan, Subhajyoti Chaudhuri, Matthew J. Guberman-Pfeffer, Dennis Vu, Sibel Ebru Yalcin, Victor S. Batista, Nikhil S. Malvankar
Summary: Geobacter sulfurreducens transports respiratory electrons over micrometers through nanowires composed of polymerized cytochrome OmcS. Individual nanowires exhibit hopping conductance and show a significant increase in their intrinsic conductance upon cooling. The cooling effect is caused by the rearrangement of hydrogen bonding networks in the nanowires, resulting in a temperature-sensitive switch for charge transport controlled by the protein surrounding the hemes.
Article
Electrochemistry
Lingling Gong, Nastaran Khodaparastasgarabad, Derek M. Hall, Jesse Greener
Summary: In this article, we propose a new microfluidic-based approach to studying electroactive biofilms. By conducting simulations and experiments, the researchers investigated microfluidic design parameters to enhance the uniformity of the boundary layer across the entire biofilm surface.
ELECTROCHIMICA ACTA
(2022)
Article
Biotechnology & Applied Microbiology
Lianbin Cao, Hongmei Sun, Yamei Ma, Mingguo Lu, Mengrui Zhao, Enzhong Li, Ying Liu
Summary: Strain Lsc-8 can produce a high current density of 33.08 mu A cm(-2) using carboxymethylcellulose (CMC) as the carbon source. By co-culturing with Geobacter sulfurreducens PCA, the current density can reach 559 mu A cm(-2), significantly higher than that of strain Lsc-8 alone. The co-culture system demonstrates excellent electricity generation capability using both CMC and raw corn stover as carbon sources.
MICROBIAL CELL FACTORIES
(2023)
