Selective butyrate production from CO and methanol in microbial electrosynthesis - influence of pH.

Methanol assisted microbial electrosynthesis (MES) enables butyrate production from carbon dioxide and methanol using external electricity. However, the effects of operational parameters on butyrate formation remain unclear. By running three flat plate MES reactors with fed-batch mode at three controlled pH values (5.

Impregnation of granular activated carbon with nickel or copper improves performance of microbial electrosynthesis.

Microbial electrosynthesis (MES) utilizes renewable electricity to power microbial conversion of carbon dioxide into multi-carbon products. As the cathode electrodes serve both as source of reducing equivalents and provide surface area for biofilm growth, the electrode material plays a crucial role in MES. In this study, granular activated carbon (GAC) was impregnated with copper or nickel (5 wt%) and used as MES cathode.

Methanol as a co-substrate with CO enhances butyrate production in microbial electrosynthesis.

Methanol is a promising feedstock for the bio-based economy as it can be derived from organic waste streams or produced electrochemically from CO. Acetate production from CO in microbial electrosynthesis (MES) has been widely studied, while more valuable compounds such as butyrate are currently attracting attention. In this study, methanol was used as a co-substrate with CO to enhance butyrate production in MES.

Anode-assisted electro-fermentation with Bacillus subtilis under oxygen-limited conditions.

Background: Bacillus subtilis is generally regarded as a ubiquitous facultative anaerobe. Oxygen is the major electron acceptor of B. subtilis, and when oxygen is absent, B.

Polyhydroxyalkanoate-driven current generation via acetate by an anaerobic methanotrophic consortium.

Anaerobic oxidation of methane (AOM) is an important microbial process mitigating methane (CH) emission from natural sediments. Anaerobic methanotrophic archaea (ANME) have been shown to mediate AOM coupled to the reduction of several compounds, either directly (i.e.

Cathodic biofilms - A prerequisite for microbial electrosynthesis.

Cathodic biofilms have an important role in CO bio-reduction to carboxylic acids and biofuels in microbial electrosynthesis (MES) cells. However, robust and resilient electroactive biofilms for an efficient CO conversion are difficult to achieve. In this review, the fundamentals of cathodic biofilm formation, including energy conservation, electron transfer and development of catalytic biofilms, are presented.

Selective Extraction of Medium-Chain Carboxylic Acids by Electrodialysis and Phase Separation.

Carboxylic acids obtained the microbial electrochemical conversion of waste gases containing carbon dioxide (, microbial electrosynthesis) can be used of nonrenewable building-block chemicals in the manufacture of a variety of products. When targeting valuable medium-chain carboxylic acids such as caproic acid, electricity-driven fermentations can be limited by the accumulation of fermentation products in the culturing media, often resulting in low volumetric productivities and titers due to direct toxicity or inhibition of the biocatalyst. In this study, we tested the effectiveness of a simple electrodialysis system in upconcentrating carboxylic acids from a model solution mimicking the effluent of a microbial electrochemical system producing short- and medium-chain carboxylic acids.

Microbial electrosynthesis system with dual biocathode arrangement for simultaneous acetogenesis, solventogenesis and carbon chain elongation.

A microbial electrosynthesis cell comprising two biological cathode chambers sharing the same anode compartment is used to promote the production of C2-C4 carboxylic acids and alcohols from carbon dioxide. Each cathode chamber provides ideal pH conditions to favor acetogenesis/carbon chain elongation (pH = 6.9), and solventogenesis (pH = 4.

Characterization of a membrane-separated and a membrane-less electrobioreactor for bioelectrochemical syntheses.

Bioelectrochemical systems (BESs) have the potential to contribute to the energy revolution driven by the new bio-economy. Until recently, simple reactor designs with minimal process analytics have been used. In recent years, assemblies to host electrodes in bioreactors have been developed resulting in so-called "electrobioreactors.

Anodic electro-fermentation: Anaerobic production of L-Lysine by recombinant Corynebacterium glutamicum.

Microbial electrochemical technologies (MET) are promising to drive metabolic processes for the production of chemicals of interest. They provide microorganisms with an electrode as an electron sink or an electron source to stabilize their redox and/or energy state. Here, we applied an anode as additional electron sink to enhance the anoxic metabolism of the industrial bacterium Corynebacterium glutamicum through an anodic electro-fermentation.

Growth of Pseudomonas taiwanensis VLB120∆C biofilms in the presence of n-butanol.

Biocatalytic processes often encounter problems due to toxic reactants and products, which reduce biocatalyst viability. Thus, robust organisms capable of tolerating or adapting towards such compounds are of high importance. This study systematically investigated the physiological response of Pseudomonas taiwanensis VLB120∆C biofilms when exposed to n-butanol, one of the potential next generation biofuels as well as a toxic substance using microscopic and biochemical methods.

Microbial electron transport and energy conservation - the foundation for optimizing bioelectrochemical systems.

Microbial electrochemical techniques describe a variety of emerging technologies that use electrode-bacteria interactions for biotechnology applications including the production of electricity, waste and wastewater treatment, bioremediation and the production of valuable products. Central in each application is the ability of the microbial catalyst to interact with external electron acceptors and/or donors and its metabolic properties that enable the combination of electron transport and carbon metabolism. And here also lies the key challenge.