Simultaneous fermentation and enzymatic biocatalysis-a useful process option?

Biotransformation with enzymes and de novo syntheses with whole-cell biocatalysts each have specific advantages. These can be combined to achieve processes with optimal performance. A recent approach is to perform bioconversion processes and enzymatic catalysis simultaneously in one-pot.

Municipal green waste as substrate for the microbial production of platform chemicals.

In Germany alone, more than 5·10 tons of municipal green waste is produced each year. So far, this material is not used in an economically worthwhile way. In this work, grass clippings and tree pruning as examples of municipal green waste were utilized as feedstock for the microbial production of platform chemicals.

Chemoorganotrophic electrofermentation by Cupriavidus necator using redox mediators.

The non-pathogenic β-proteobacterium Cupriavidus necator has the ability to switch between chemoorganotrophic, chemolithoautotrophic and electrotrophic growth modes, making this microorganism a widely used host for cellular bioprocesses. Oxygen usually acts as the terminal electron acceptor in all growth modes. However, several challenges are associated with aeration, such as foam formation, oxygen supply costs, and the formation of an explosive gas mixture in chemolithoautotrophic cultivation with H, CO and O.

Anti-inflammatory effects of α-humulene on the release of pro-inflammatory cytokines in lipopolysaccharide-induced THP-1 cells.

While acute inflammation is an essential physical response to harmful external influences, the transition to chronic inflammation is problematic and associated with the development and worsening of many deadly diseases. Until now, established pharmaceutical agents have had many side effects when used for long periods. In this study, a possible anti-inflammatory effect of the sesquiterpene α-humulene on lipopolysaccharide (LPS) induction was tested.

New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum.

Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes.

Metabolic engineering of Shewanella oneidensis to produce glutamate and itaconic acid.

Shewanella oneidensis is a gram-negative bacterium known for its unique respiratory capabilities, which allow it to utilize a wide range of electron acceptors, including solid substrates such as electrodes. For a future combination of chemical production and electro-fermentation, the goal of this study was to expand its product spectrum. S.

Coupling of CO Electrolysis with Parallel and Semi-Automated Biopolymer Synthesis - Ex-Cell and without Downstream Processing.

Important improvements have been achieved in developing the coupling of electrochemical CO reduction to formate with its subsequent microbial conversion to polyhydroxybutyrate (PHB) by Cupriavidus necator. The CO based formate electrosynthesis was optimised by electrolysis parameter adjustment and application of Sn based gas diffusion electrodes reaching almost 80 % Faradaic efficiency at 150 mA cm. Thereby, catholyte with the high formate concentration of 441±9 mmol L was generated as feedstock without intermediate downstream processing for semi-automated formate feeding into a fed-batch reactor system.

Autotrophic Production of the Sesquiterpene α-Humulene with in a Controlled Bioreactor.

is a facultative chemolithotrophic organism that grows under both heterotrophic and autotrophic conditions. It is becoming increasingly important due to its ability to convert CO into industrially valuable chemicals. To translate the potential of into technical applications, it is necessary to optimize and scale up production processes.

Electrochemical HO - stat mode as reaction concept to improve the process performance of an unspecific peroxygenase.

The electroenzymatic hydroxylation of 4-ethylbenzoic acid catalyzed by the recombinant unspecific peroxygenase from the fungus Agrocybe aegerita (rAaeUPO) was performed in a gas diffusion electrode (GDE)-based system. Enzyme stability and productivity are significantly affected by the way the co-substrate hydrogen peroxide (HO) is supplied. In this study, two in-situ electrogeneration modes of HO were established and compared.

Antibiofilm assay for antimicrobial peptides combating the sulfate-reducing bacteria Desulfovibrio vulgaris.

In medical, environmental, and industrial processes, the accumulation of bacteria in biofilms can disrupt many processes. Antimicrobial peptides (AMPs) are receiving increasing attention in the development of new substances to avoid or reduce biofilm formation. There is a lack of parallel testing of the effect against biofilms in this area, as well as in the testing of other antibiofilm agents.

Contribution of Enzyme Catalysis to the Achievement of the United Nations' Sustainable Development Goals.

In September 2015, the United Nations General Assembly established the 2030 Agenda for Sustainable Development, which includes 17 Sustainable Development Goals (SDGs) [...

Optimization of antimicrobial peptides for the application against biocorrosive bacteria.

Microbiologically influenced corrosion is a common problem in the industrial field due to the deterioration of metals in the presence of various microorganisms, in particular sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). A common method to reduce microbiologically influenced corrosion is the application of biocides. The limited number of suitable biocides and the resulting development of resistance, high dosage, and high application rate hinder an effective application.

Anodic Respiration of Vibrio natriegens in a Bioelectrochemical System.

Vibrio natriegens promises to be a new standard biotechnological working organism since it grows extraordinarily fast, its productivity surpasses E. coli by far, and genomic tools are getting readily available. Recent studies provided insights into its extracellular electron transfer pathway, revealing it to be similar to other well-known electroactive organisms.

Analyzing and understanding the robustness of bioprocesses.

The robustness of bioprocesses is becoming increasingly important. The main driving forces of this development are, in particular, increasing demands on product purities as well as economic aspects. In general, bioprocesses exhibit extremely high complexity and variability.

Contribution of electrobiotechnology to sustainable development goals.

The UN Sustainable Development Goals (SDGs) are 17 interlinked goals designed to be a 'shared blueprint for peace and prosperity for people and the planet, now and into the future'. Therefore, global efforts should focus on achieving these. Herein, we discuss the contribution of electrobiotechnology to the realization of the SDGs.

Application of gas diffusion electrodes in bioeconomy: An update.

The transition of today's fossil fuel based chemical industry toward sustainable production requires improvement of established production processes as well as development of new sustainable and bio-based synthesis routes within a circular economy. Thereby, the combination of electrochemical and biotechnological advantages in such routes represents one important keystone. For the electrochemical generation of reactants from gaseous substrates such as O or CO , gas diffusion electrodes (GDE) represent the electrodes of choice since they overcome solubility-based mass transport limitations.

Identification of vitamin B producing bacteria based on the presence of bluB/cobT2 homologues.

Objectives: The objective of the study was to develop a strategy for the identification of new vitamin B-producing species and to characterize their production capability using a fast and sensitive LC-MS/MS method developed in this study.

Results: Searching for homologues of the bluB/cobT2 fusion gene known to be responsible for the production of the active vitamin B form in P. freudenreichii was shown to be a successful strategy for the identification of new vitamin B-producing strains.

Fermentative α-Humulene Production from Homogenized Grass Clippings as a Growth Medium.

Green waste, e.g., grass clippings, is currently insufficiently recycled and has untapped potential as a valuable resource.

Flexible biofilm monitoring device.

Biofilms and their analysis are increasingly attracting the attention of the scientific community due to the immense importance and impact of biofilms in various natural, technical and medical fields. For these purposes, an optimized and extended antibiofilm assay system based on the Calgary Biofilm Device (MBEC Assay® system) consisting of microtiter plate and PCR tubes was established. Its implementation was used to study the growth characteristics of the sessile phenotype of exposed to antimicrobial peptides.

Enhanced Electron Uptake and Methane Production by Corrosive Methanogens during Electromethanogenesis.

Electromethanogenesis is an interesting next-generation technology to produce methane from CO and electricity by using methanogens. Iron-corroding methanogens might be of special interest for that application due to their natural ability for electron uptake. Mic1c10 and KA1 were tested in bioelectrochemical systems.

Methylotrophic bacteria with cobalamin-dependent mutases in primary metabolism as potential strains for vitamin B production.

Several bacterial species are known for their ability to synthesize vitamin B but biotechnological vitamin B production today is restricted to Pseudomonas denitrificans and Propionibacterium freudenreichii. Nevertheless, the rising popularity of veganism leads to a growing demand for vitamin B and thereby interest in alternative strains which can be used as efficient vitamin B sources. In this work, we demonstrate that methylotrophic microorganisms which utilize the ethylmalonyl-CoA pathway containing B-dependent enzymes are capable of active vitamin B production.

Geobacter sulfurreducens metabolism at different donor/acceptor ratios.

Geobacter species have great application potential in remediation processes and electrobiotechnology. In all applications, understanding the metabolism will enable target-oriented optimization of the processes. The typical electron donor and carbon source of the Geobacter species is acetate, while fumarate is the usual electron acceptor.

Upgrading Kolbe Electrolysis-Highly Efficient Production of Green Fuels and Solvents by Coupling Biosynthesis and Electrosynthesis.

The chemical industry is transitioning to more sustainable and biobased processes. One key element of this transition is coupling energy fluxes and feedstock utilization for optimizing processes, routes and efficiencies. Here, we show for the first time the coupling of the Kolbe electrolysis at the anode with a subsequent microbial conversion of the cathodically produced co-product hydrogen.

Influence of electrode surface charge on current production by Geobacter sulfurreducens microbial anodes.

Positively charged electrode surfaces are thought to enhance electrostatic interaction with mostly negatively charged bacteria cell surface, thereby improving microbial fuel cell performance. In this work, electrostatic self-assembly of charged polymers was used to systematically modify the surface of indium tin coated electrodes. Evaluation was based on start-up time, maximum current, biofilm thickness and coulombic efficiency of microbial Geobacter sulfurreducens anodes.

Microbial electrosynthesis of methane and acetate-comparison of pure and mixed cultures.

The electrochemical process of microbial electrosynthesis (MES) is used to drive the metabolism of electroactive microorganisms for the production of valuable chemicals and fuels. MES combines the advantages of electrochemistry, engineering, and microbiology and offers alternative production processes based on renewable raw materials and regenerative energies. In addition to the reactor concept and electrode design, the biocatalysts used have a significant influence on the performance of MES.