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Abstract Global developments such as climate change, a growing world population and the depletion of fossil resources make the sustainable use of biogenic resources in chemical production inevitable. This would also provide a final product with a higher added value than just utilizing the raw materials for applications in energy generation. In recent years, many researchers have shown that e.g., grass clippings, carrots and potato peels can be biotechnologically converted into high-value chemicals thereby increasing resource efficiency. A particular challenge, however, is the decentralized production of such biogenic raw materials as well as degradation affecting the composition and quality within short periods of time. Therefore, appropriate logistics concepts must be developed and evaluated to economically valorize biogenic raw materials. Such concepts differ significantly in terms of material utilization for the production of chemicals, composting or energetic valorization. This overview presents relevant examples of the conversion of biogenic residues into chemicals investigating basic logistic concepts and highlighting major challenges along bio-based value chains.

Abstract 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. This is a well-established process in the biorefinery, where starchy or cellulosic material is degraded enzymatically and simultaneously used as substrate for microbial cultivations. This procedure leads to a number of advantages like saving in time but also in the needed equipment (e.g., reaction vessels). In addition, the inhibition or side-reaction of high sugar concentrations can be overcome by combining the processes. These benefits of coupling microbial conversion and enzymatic biotransformation can also be transferred to other processes for example in the sector of biofuel production or in the food industry. However, finding a compromise between the different requirements of the two processes is challenging in some cases. This article summarises the latest developments and process variations. Graphical Abstract

Abstract Cable bacteria, characterized by their multicellular filamentous growth, are prevalent in both freshwater and marine sediments. They possess the unique ability to transport electrons over distances of centimeters. Coupled with their capacity to fix CO2 and their record‐breaking conductivity for biological materials, these bacteria present promising prospects for bioprocess engineering, including potential electrochemical applications. However, the cultivation of cable bacteria has been limited to their natural sediment, constraining their utility in production processes. To address this, our study designs synthetic sediment, drawing on ion exchange chromatography data from natural sediments and existing literature on the requirements of cable bacteria. We examined the effects of varying bentonite concentrations on water retention and the impacts of different sands. For the first time, we cultivated cable bacteria on synthetic sediment, specifically the freshwater strain Electronema aureum GS. This cultivation was conducted over 10 weeks in a specially developed sediment bioreactor, resulting in an increased density of cable bacteria in the sediment and growth up to a depth of 5 cm. The creation of this synthetic sediment paves the way for the reproducible cultivation of cable bacteria. It also opens up possibilities for future process scale‐up using readily available components. This advancement holds significant implications for the broader field of bioprocess engineering.

One major obstacle to the commercialization of electrobiotechnological systems is the cost of materials, including expensive electrodes. Smart recycling as well as the use of renewable resources can contribute to producing electrodes more ecologically and economically. Green waste is a biogenic residual material that occurs mainly in urban areas and is currently not recycled to a sufficient extent. Here we show the fabrication of electrodes from carbonized grass clippings and their application in microbial electrosynthesis as well as microbial fuel cells. While the electrodes cannot compete with established metal competitors for water electrolysis in microbial electrosynthesis, they perform comparably to commercial graphite electrodes in microbial fuel cells. With Geobacter sulfurreducens, a current response can be recorded for more than six weeks. To the best of our knowledge, this is the first time that carbonized green waste has been used as an electrode material for bioelectrochemical systems. This demonstrates the potential of carbonized biological materials as a raw material for electrodes and presents a recycling alternative for green waste.

The aim of this work was to produce the biopolymer polyhydroxybutyrate (PHB) from industrial flue gas as CO2 source and electrolysis originating hydrogen via microbial electrosynthesis. Besides the laboratory experiments, the experiments were carried out under industrial conditions directly on-site in a cogeneration plant. We were able to demonstrate that the use of flue gas as a CO2 source has no detectable negative effect on bacterial growth and PHB production in comparison to a pure gas mixture. In an electrochemical H-cell 333 ± 44 mg L−1 PHB were obtained, which corresponds to a PHB content of 43 ± 3 % of the cell dry weight. By using flue gas for the production of the biopolymer PHB, not only CO2 emissions are reduced, but also possible environmental pollution from non-biodegradable plastics. To the best of our knowledge, this is the first time that the production of PHB from flue gas has been demonstrated using Cupriavidus necator.

This work examines the electrochemically enhanced production of succinic acid using the bacterium Actinobacillus succinogenes. The principal objective is to enhance the metabolic potential of glucose and CO2 utilization via the C4 pathway in order to synthesize succinic acid. We report on the development of an electro-bioreactor system to increase succinic acid production in a power-2-X approach. The use of activated carbon fibers as electrode surfaces and contact areas allows A. succinogenes to self-initiate biofilm formation. The integration of an electrical potential into the system shifts the redox balance from NAD+ to NADH, increasing the efficiency of metabolic processes. Mediators such as neutral red facilitate electron transfer within the system and optimize the redox reactions that are crucial for increased succinic acid production. Furthermore, the role of carbon nanotubes (CNTs) in electron transfer was investigated. The electro-bioreactor system developed here was operated in batch mode for 48 h and showed improvements in succinic acid yield and concentration. In particular, a run with 100 µM neutral red and a voltage of −600 mV achieved a yield of 0.7 gsuccinate·gglucose−1. In the absence of neutral red, a higher yield of 0.72 gsuccinate·gglucose−1 was achieved, which represents an increase of 14% compared to the control. When a potential of −600 mV was used in conjunction with 500 µg∙L−1 CNTs, a 21% increase in succinate concentration was observed after 48 h. An increase of 33% was achieved in the same batch by increasing the stirring speed. These results underscore the potential of the electro-bioreactor system to markedly enhance succinic acid production.

Abstract In Germany alone, more than 5·106 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. A pretreatment procedure depending on the moisture and lignin content of the biomass was developed. The suitability of grass press juice and enzymatic hydrolysate of lignocellulosic biomass pretreated with an organosolv process as fermentation medium or medium supplement for the cultivation of Saccharomyces cerevisiae, Lactobacillus delbrueckii subsp. lactis, Ustilago maydis, and Clostridium acetobutylicum was demonstrated. Product concentrations of 9.4 gethanol L−1, 16.9 glactic acid L−1, 20.0 gitaconic acid L−1, and 15.5 gsolvents L−1 were achieved in the different processes. Yields were in the same range as or higher than those of reference processes grown in established standard media. By reducing the waste arising in cities and using municipal green waste as feedstock to produce platform chemicals, this work contributes to the UN sustainability goals and supports the transition toward a circular bioeconomy. Graphical Abstract

Digitale Medien sind elementarer Bestandteil in Lehr-Lern-Prozessen und stehen im Einklang mit den physischen, medialen und virtuellen Lebensräumen der Schüler:innen indem sie Gegenwarts- und insbesondere auch eine Zukunftsbedeutung für die Heranwachsenden haben. Die didaktisch-methodische Reflektion und Bewertung von technologischen Innovationen aus dem Internet of Things (IoT) oder der Industrie 4.0 ermöglichen es, grundlegende Aussagen zu fächerspezifischen sowie fächerübergreifenden Potentialen zum Einsatz im schulischen Kontext zu formulieren. In diesem Beitrag werden die Potentiale für ein gelingendes Lehren und Lernen in der naturwissenschaftlichen Bildung von digitalen Zwillingen zusammenfassend betrachtet. Digitale Zwilling sind bereits in der industriellen Prozessentwicklung und -optimierung implementiert. Grundsätzlich nehmen die, in digitalen Zwillingen, repräsentierten Vernetzungsstrukturen zwischen digitaler und realer Welt und deren Potential in den Bereichen künstliche Intelligenz, maschinelles Lernen und Data-Mining-Prozessen einen wesentlichen Fokus ein. Um Bildungsperspektiven für den naturwissenschaftlichen Unterricht abzuleiten, werden die eingehenden und ausgehenden Datenstrukturen und deren Funktionsweisen in digitalen Zwillingen näher betrachtet. Der Beitrag thematisiert den Blick auf digitale Zwillinge als intelligente neue Bildungstechnologie in Lehr-Lern-Prozessen, welche auch im industriellen Sektor noch nicht an ihrem Entwicklungsendpunkt steht und vielfältige Anwendungspotentiale im Schulkontext, viele offene Forschungsfragen und Entwicklungspotentiale im Rahmen der Bildungsforschung bereithalten.

Abstract This study introduced an automated long‐term fermentation process for fungals grown in pellet form. The goal was to reduce the overgrowth of bioreactor internals and sensors while better rheological properties in the fermentation broth, such as oxygen transfer and mixing time, can be achieved. Because this could not be accomplished with continuous culture and fed‐batch fermentation, repeated‐batch fermentation was implemented with the help of additional bioreactor internals (“sporulation supports”). This should capture some biomass during fermentation. After harvesting the suspended biomass, intermediate cleaning was performed using a cleaning device. The biomass retained on the sporulation support went through the sporulation phase. The spores were subsequently used as inocula for the next batch. The reason for this approach was that the retained pellets could otherwise cause problems (e.g., overgrowth on sensors) in subsequent batches because the fungus would then show undesirable hyphal growth. Various sporulation supports were tested for sufficient biomass fixation to start the next batch. A reproducible spore concentration within the range of the requirements could be achieved by adjusting the sporulation support (design and construction material), and an intermediate cleaning adapted to this.

Fucoidan is a class of multifunctional polysaccharides derived from marine organisms. Its unique and diversified physicochemical and chemical properties have qualified them for potential and promising pharmacological uses in human diseases, including inflammation, tumors, immunity disorders, kidney diseases, and diabetes. Physicochemical and chemical properties are the main contributors to these bioactivities. The previous literature has attributed such activities to its ability to target key enzymes and receptors involved in potential disease pathways, either directly or indirectly, where the anionic sulfate ester groups are mainly involved in these interactions. These findings also confirm the advantageous pharmacological uses of sulfated versus non-sulfated polysaccharides. The current review shall highlight the molecular targets of fucoidans, especially enzymes, and the subsequent responses via either the upregulation or downregulation of mediators’ expression in various tissue abnormalities. In addition, in silico studies will be applied to support the previous findings and show the significant contributors. The current review may help in understanding the molecular mechanisms of fucoidan. Also, the findings of this review may be utilized in the design of specific oligomers inspired by fucoidan with the purpose of treating life-threatening human diseases effectively.