Influence of Different Transposon Families on Genomic Stability of Shewanella oneidensis MR1.

Shewanella oneidensis, recognised as an important model organism for exoelectrogenic electron transport, has been extensively studied for its potential applications in bioelectrochemical systems. To date, the activity of transposable elements in this organism has not been conclusively investigated. This study focused on transposases, specifically insertion sequences (IS), which make up approximately 4.

Opinion on Biofilms as Production Systems.

Biofilm-based production systems offer enhanced robustness, higher biomass densities and improved genetic stability compared to traditional stirred tank reactors, presenting promising alternatives for sustainable, efficient biotechnological manufacturing despite challenges in reactor design and process control.

Tailored enzyme expression modifies Shewanella oneidensis biofilms and increases current density.

Biofilm formation is the most effective pathway for electron transfer to anodes in bioelectrochemical systems. However, the mechanisms triggering biofilm formation under anoxic conditions, as well as the architectural and compositional factors that positively influence current generation, are not well understood. Recent findings have shown that riboflavin can function similarly to a quorum sensing molecule in the γ-proteobacterium Shewanella oneidensis.

Identification of factors limiting the efficiency of transplanting extracellular electron transfer chains in .

Research in electro-microbiology provides unique opportunities to study and exploit microbial physiology. Several efforts have been made to transplant the extracellular electron transport chain from the native exoelectrogenic model organism into . However, systematic comparisons between donor and recipient strain configurations are largely missing.

Extracellular Bacterial Production of DNA Hydrogels-Toward Engineered Living Materials.

Engineered Living Materials (ELMs) combine synthetic biology with artificial materials to create biohybrid living systems capable of replicating, self-repairing, and responding to external stimuli. Due to their self-optimization abilities, these systems hold great potential for biotechnological applications. This study is a first step toward ELMs based on DNA hydrogels, focusing on the production of biohybrid materials using the exoelectrogenic bacterium Shewanella oneidensis.

Magnetic, conductive nanoparticles as building blocks for steerable micropillar-structured anodic biofilms.

In bioelectrochemical systems (BES), biofilm formation and architecture are of crucial importance, especially for flow-through applications. The interface between electroactive microorganisms and the electrode surface plays an important and often limiting role, as the available surface area influences current generation, especially for poor biofilm forming organisms. To overcome the limitation of the available electrode surface, nanoparticles (NPs) with a magnetic iron core and a conductive, hydrophobic carbon shell were used as building blocks to form conductive, magnetic micropillars on the anode surface.

Efficiency and process development for microbial biomass production using oxic bioelectrosynthesis.

Autotrophic microbial electrosynthesis (MES) processes are mainly based on organisms that rely on carbon dioxide (CO) as an electron acceptor and typically have low biomass yields. However, there are few data on the process and efficiencies of oxic MES (OMES). In this study, we used the knallgas bacterium Kyrpidia spormannii to investigate biomass formation and energy efficiency of cathode-dependent growth.

Strategic improvement of Shewanella oneidensis for biocatalysis: Approach to media refinement and scalable application in a microbial electrochemical system.

Microbial electrochemical systems offer a sustainable method for the conversion of chemical energy into electrical energy or hydrogen and the production of valuable compounds, contributing to the development of a bio-based economy. This study aimed to enhance the performance of anodic bioelectrochemical systems by improving the current density of Shewanella oneidensis as a biocatalyst through strain modification and medium refinement. The genetic modification, combining the prophage deletion and overexpression of the speC gene, resulted in a 4.

Shewanella oneidensis: Biotechnological Application of Metal-Reducing Bacteria.

What is an unconventional organism in biotechnology? The γ-proteobacterium Shewanella oneidensis might fall into this category as it was initially established as a laboratory model organism for a process that was not seen as potentially interesting for biotechnology. The reduction of solid-state extracellular electron acceptors such as iron and manganese oxides is highly relevant for many biogeochemical cycles, although it turned out in recent years to be quite relevant for many potential biotechnological applications as well. Applications started with the production of nanoparticles and dramatically increased after understanding that electrodes in bioelectrochemical systems can also be used by these organisms.

Illuminating bioprocess responses to metal-based nanoparticles addition along hydrogen and methane production pathways: A review.

Recent research has discussed the positive impacts of metal-based nanoparticles (NPs) on bioprocesses producing either hydrogen (H) or methane (CH). The enhancement has been explained by mechanisms such as direct interspecies electron transfer (DIET), metal corrosion, and dissimilatory reduction. Such interactions could induce further benefits, such as controlling oxidation-reduction potential (ORP), mitigating toxicants, promoting enzymatic activity, and altering the microbiome, which have not yet been comprehensively discussed.

Comparative analysis of the influence of BpfA and BpfG on biofilm development and current density in Shewanella oneidensis under oxic, fumarate- and anode-respiring conditions.

Biofilm formation by Shewanella oneidensis has been extensively studied under oxic conditions; however, relatively little is known about biofilm formation under anoxic conditions and how biofilm architecture and composition can positively influence current generation in bioelectrochemical systems. In this study, we utilized a recently developed microfluidic biofilm analysis setup with automated 3D imaging to investigate the effects of extracellular electron acceptors and synthetic modifications to the extracellular polymeric matrix on biofilm formation. Our results with the wild type strain demonstrate robust biofilm formation even under anoxic conditions when fumarate is used as the electron acceptor.

Strain and model development for auto- and heterotrophic 2,3-butanediol production using Cupriavidus necator H16.

The production of platform chemicals from renewable energy sources is a crucial step towards a post-fossil economy. This study reports on the production of acetoin and 2,3-butanediol heterotrophically with fructose as substrate and autotrophically from CO as carbon source, H as electron donor and O as electron acceptor with Cupriavidus necator. In a previous study, the strain was developed for the production of acetoin with high carbon efficiency.

Elucidating the development of cooperative anode-biofilm-structures.

Microbial electrochemical systems are a highly versatile platform technology with a particular focus on the interplay of chemical and electrical energy conversion and offer immense potential for a sustainable bioeconomy. The industrial realization of this potential requires a critical focus on biofilm optimization if performance is to be controlled over a long period of time. Moreover, the aspect and influence of cooperativity has to be addressed as many applied anodic bioelectrochemical systems will most likely be operated with a diversity of interacting microbial species.

Biofilms for Production of Chemicals and Energy.

The twenty-first century will be the century of biology. This is not only because of breakthrough advances in molecular biology tools but also because we need to reinvent our economy based on the biological principles of energy efficiency and sustainability. Consequently, new tools for production routines must be developed to help produce platform chemicals and energy sources based on sustainable resources.

Beneficial applications of biofilms.

Many microorganisms live in the form of a biofilm. Although they are feared in the medical sector, biofilms that are composed of non-pathogenic organisms can be highly beneficial in many applications, including the production of bulk and fine chemicals. Biofilm systems are natural retentostats in which the biocatalysts can adapt and optimize their metabolism to different conditions over time.

Gastropods as a source for fecal indicator bacteria in drinking water.

Microbial water quality is routinely examined using the fecal indicator bacteria Escherichia coli, coliform bacteria and enterococci. Several practical cases in German drinking water distribution systems indicated invertebrates such as insects or gastropods as a source for the microbiological deterioration. Therefore, we examined three genera of Gastropoda (Arion, Helix and Cepaea) for the presence of fecal indictor bacteria in excreta using standard methods.

Microbe-Anode Interactions: Comparing the impact of genetic and material engineering approaches to improve the performance of microbial electrochemical systems (MES).

Microbial electrochemical systems (MESs) are a highly versatile platform technology with a particular focus on power or energy production. Often, they are used in combination with substrate conversion (e.g.

Probing the robustness of Geobacter sulfurreducens against fermentation hydrolysate for uses in bioelectrochemical systems.

In this study, impacts of toxic ions/acids found in real fermentation-hydrolysate on the model exoelectrogenic G. sulfurreducens were investigated. Initially, different concentrations of acetate, butyrate, propionate, Na, and K were tested, individually and in combination, for effects on the planktonic growth, followed by validation with diluted-hydrolysate.

Electron transfer of extremophiles in bioelectrochemical systems.

The interaction of bacteria and archaea with electrodes is a relatively new research field which spans from fundamental to applied research and influences interdisciplinary research in the fields of microbiology, biochemistry, biotechnology as well as process engineering. Although a substantial understanding of electron transfer processes between microbes and anodes and between microbes and cathodes has been achieved in mesophilic organisms, the mechanisms used by microbes under extremophilic conditions are still in the early stages of discovery. Here, we review our current knowledge on the biochemical solutions that evolved for the interaction of extremophilic organisms with electrodes.

Sprayable biofilm - Agarose hydrogels as 3D matrix for enhanced productivity in bioelectrochemical systems.

Bio-based energy production utilizing renewable resources can be realized by exoelectrogenic organisms and their application in bioelectrochemical systems (BES). These organisms catalyze the direct conversion of chemical into electrical energy and are already widely used in bioelectronics and biosensing. However, the biofilm-electrode interaction is a factor that limits sufficient space-time-yields for industrial applications.

Microbially promoted calcite precipitation in the pelagic redoxcline: Elucidating the formation of the turbid layer.

Large bell-shaped calcite formations called "Hells Bells" were discovered underwater in the stratified cenote El Zapote on the Yucatán Peninsula, Mexico. Together with these extraordinary speleothems, divers found a white, cloudy turbid layer into which some Hells Bells partially extend. Here, we address the central question if the formation of the turbid layer could be based on microbial activity, more specifically, on microbially induced calcite precipitation.

The importance of biofilm formation for cultivation of a Micrarchaeon and its interactions with its Thermoplasmatales host.

Micrarchaeota is a distinctive lineage assigned to the DPANN archaea, which includes poorly characterised microorganisms with reduced genomes that likely depend on interactions with hosts for growth and survival. Here, we report the enrichment of a stable co-culture of a member of the Micrarchaeota (Ca. Micrarchaeum harzensis) together with its Thermoplasmatales host (Ca.

Nanowired electrodes as outer membrane cytochrome-independent electronic conduit in .

Extracellular electron transfer (EET) from microorganisms to inorganic electrodes is a unique ability of electrochemically active bacteria. Despite rigorous genetic and biochemical screening of the -type cytochromes that make up the EET network, the individual electron transfer steps over the cell membrane remain mostly unresolved. As such, attempts to transplant entire EET chains from native into non-native exoelectrogens have resulted in inferior electron transfer rates.

Enrichment of phosphate-accumulating organisms (PAOs) in a microfluidic model biofilm system by mimicking a typical aerobic granular sludge feast/famine regime.

Wastewater treatment using aerobic granular sludge has gained increasing interest due to its advantages compared to conventional activated sludge. The technology allows simultaneous removal of organic carbon, nitrogen, and phosphorus in a single reactor system and is independent of space-intensive settling tanks. However, due to the microscale, an analysis of processes and microbial population along the radius of granules is challenging.

A Micrarchaeon Isolate Is Covered by a Proteinaceous S-Layer.

In previous publications, it was hypothesized that cells are covered by two individual membrane systems. This study proves that at least the recently cultivated " Micrarchaeum harzensis A_DKE" possesses an S-layer covering its cytoplasmic membrane. The potential S-layer protein was found to be among the proteins with the highest abundance in " Micrarchaeum harzensis A_DKE," and characterization of its primary structure indicated homologies to other known S-layer proteins.