Artificial intelligence with neural networks performs calculations digitally with the help of microelectronic chips. Physicists at Leipzig University have now realised a form of neural network that works not with electricity but with so-called active colloidal particles. In their publication in the renowned journal “Nature Communications”, the aim is to use these microparticles as a physical system for artificial intelligence and the prediction of time series.
In the REPLACER project, researchers are developing so-called hybrid living materials. The focus is on producing microbial proteins with a low carbon footprint, high acceptance and affordable costs – by using greenhouse gases. The long-term goal: sustainable production of feed proteins. An example of applied research with great transfer potential. The Research and Transfer Centre for Bioactive Matter (b-ACT matter) is coordinating the project.
Electrons and microbes are the decisive factor in this
Until now, nylon has been produced from petroleum-based raw materials. However, this is quite harmful to the environment because non-renewable fossil resources are used, a great deal of energy is required, and climate-damaging nitrous oxide is emitted during production. A research team from the Helmholtz Centre for Environmental Research (UFZ) and the Leipzig University has now developed a process that can produce adipic acid, one of two building blocks of nylon, from phenol through electrochemical synthesis and the use of microorganisms. The team also showed that phenol can be replaced by waste materials from the wood industry. This could then be used to produce bio-based nylon. The research work was published in Green Chemistry.
In T-shirts, stockings, shirts, and ropes – or as a component of parachutes and car tyres – polyamides are used everywhere as synthetic fibres. At the end of the 1930s, the name Nylon was coined for such synthetic polyamides. Nylon-6 and Nylon-6.6 are two polyamides that account for around 95% of the global nylon market. Until now, they have been produced from fossil-based raw materials. However, this petrochemical process is harmful to the environment because it emits around 10% of the climate-damaging nitrous oxide (laughing gas) worldwide and requires a great deal of energy. “Our goal is to make the entire nylon production chain environmentally friendly. This is possible if we access bio-based waste as feedstock and make the synthesis process sustainable”, says Dr Falk Harnisch, head of the Electrobiotechnology working group at the Helmholtz Centre for Environmental Research (UFZ).
The Leipzig researchers led by Falk Harnisch and Dr Rohan Karande (University of Leipzig/Research and Transfer Center for bioactive Matter b-ACTmatter) have described how this can be achieved in an article published in Green Chemistry. For example, nylon consists of about 50% adipic acid, which has so far been industrially extracted from petroleum. In a first step, phenol is converted to cyclohexanol, which is then converted to adipic acid. This energy-intensive process requires high temperatures, high gas pressure, and a large amount of organic solvents. It also releases a lot of nitrous oxide and carbon dioxide. The researchers have now developed a process in which they can convert phenol into cyclohexanol using an electrochemical process. “The chemical transformation behind it is the same as in the established processes. However, electrochemical synthesis replaces the hydrogen gas with electric energy which takes place in an aqueous solution and requires only ambient pressure and temperature”, explains Harnisch. For this reaction to run as quickly and efficiently as possible, a suitable catalyst is needed. This would maximise the yield of electrons needed for the reaction and the efficiency of the conversion of phenol to cyclohexanol. In laboratory experiments, the best yields (almost 70% electrons and just over 70% cyclohexanol) were shown with a carbon-based rhodium catalyst. “The relatively short reaction time, the efficient yield, and the effective use of energy as well as synergies with the biological system make this process attractive for a combined production of adipic acid”, says Dr Micjel Chávez Morejón, UFZ-chemist and first author of the study. In earlier research, two other UFZ working groups led by Dr Katja Bühler and Dr Bruno Bühler discovered how the bacterium Pseudomonas taiwanensis can convert cyclohexanol into adipic acid in a second step. “Until now, it had not been possible to microbially convert phenol to cyclohexanol. We have closed this gap with the electrochemical reaction.”, says Dr Rohan Karande, who is now continuing this work in cooperation with the UFZ at the University of Leipzig.
The Leipzig researchers were able to close yet another gap in environmentally friendly nylon production by developing an alternative for phenol produced from fossil-based raw materials. To do this, they used monomers such as syringol, catechol, and guaiacol, all of which are produced as a degradation product of lignin – a waste product of the wood industry. “For these model substances, we have been able to show that together we can go all the way to adipic acid.”, says Harnisch. Rohan Karande adds: “Around 4.5 million tonnes of adipic acid are produced worldwide. If we were to use waste products from the wood industry for this, it would have a considerable effect on the world market.”.
However, there is still a long way to go before lignin-based nylon is ready for the market. For example, the scientists have so far achieved a yield of 57% for the 22-hour overall process (i.e. from the monomers from lignin residues by means of microbial and electrochemical reaction steps to adipic acid). “This a very good yield”, says Micjel Chávez Morejón. The results are still based on laboratory tests on a millilitre scale. The prerequisites for scaling up the process are to be created in the next two years. This technology transfer requires not only a better understanding of the entire process but also, among other things, the use of real lignin mixtures instead of model mixtures (as has been the case so far) and the improvement of the electrochemical reactors. Harnisch and Karande agree: “The process for the lignin-based nylon exemplifies the great potential of electrochemical–microbial processes because an optimal process chain can be set up through the intelligent way in which various components are combined”.
The process for developing biobased nylon is funded by the UFZ’s “transfun” innovation programme, which supports the translation of ideas into applications at the UFZ. The project funding of 250,000 euros is supplemented by the University of Leipzig’s own contributions.
Publication: Micjel Chávez Morejón, Alexander Franz, Rohan Karande, and Falk Harnisch: Integrated electrosynthesis and biosynthesis for the production of adipic acid from lignin-derived phenols. Green Chemistry, https://doi.org/10.1039/D3GC01105D
Further information: Dr Falk Harnisch Group Leader Electrobiotechnology, Department of Environmental Microbiology E-Mail
Climate change, plastic pollution, and food insecurity are existential threats and pose tremendous challenges to Europe and the world. The M-era.Net / Free State of Saxony granted REPLACER project “Recycling plastic and developing hybrid living materials by capturing greenhouse gases to produce value-added products“ focuses on addressing these challenges by combining the advantages of the living and non-living worlds to develop hybrid living materials (HLMs) and enabling the sustainable production of feed proteins. The Research and Transfer Center for bioactive matter (b-ACTmatter), Leipzig University, coordinates the REPLACER project.
According to Dr. Rohan Karande, scientific and technological innovations aiming to reduce greenhouse gases and plastic waste while presenting a sustainable solution to the current feed production system are urgently needed to overcome climate change, plastic pollution, and food insecurity issues. To tackle these challenges, the REPLACER project will dedicate efforts to designing and scaling HLM-based bioreactor prototypes to produce microbial biomass as a value-added feed product from CO2 and CH4. We hope to test the pilot scale prototype in 3 – 4 years.
REPLACER is one of the 9 successfully evaluated projects out of 82 submitted proposals to the M-ERA.NET 2022 call topic “Functional materials”. The project developments will contribute to the EU Commission’s European Green Deal and Circular Economy Action Plan goals of developing advanced, resource-efficient technologies supporting a circular economy. In addition, REPLACER targets to mitigate GHGs, reduce plastic pollution, and produce value-added feed products, thus supporting several of the relevant UN sustainable development goals (SDGs).
At Leipzig University, the consortium is led by the b-ACTmatter -team; Dr.-Ing. Rohan Karande (coordinator), Prof. Frank Cichos, Dr. Susanne Ebitsch, Prof. Oskar Hallatschek, and Prof. Tilo Pompe. Within the Leipzig region of Saxony, the project establishes a close connection between research at Leipzig University, the Leibniz Institute of Surface Engineering (IOM), and the material technology company “qCOAT”. On the European level, the consortium involves partners from the University of Latvia, Latvia, and Holisun SRL, Romania.
How can innovations get into practice faster? Dr. Susanne Ebitsch, Managing Director of the Research and Transfer Center for Bioactive Materials, bACTmatter at the University of Leipzig, shows how knowledge and technology transfer out of the university could be accelerated and improved.
Recently, our Eurostars project “SoftKollP: the first portable biosensor for quantitative field monitoring of anthropogenic contaminants in the environment” started.
Together with our partners HiSS Diagnostics GmbH (lead, Freiburg and Leipzig) and ECTICA TECHNOLOGIES AG (Zurich), we aim at bringing to the market the SoftKollP technology, as the first highly sensitive technology for fast, easy-to-use, cheap and quantitative point-of use monitoring of anthropogenic contaminants in the environment and agricultural sector. The SoftKollP technology is based on soft hydrogel microparticles and was invented at Leipzig University and TU Dresden. As the market entry product line, we will develop SoftKollP for the critically discussed and widely distributed herbicide glyphosate and its persistent degradation product AMPA.
Rebecca Graul (HiSS) and Benjamin Simon (CEO ECTICA) visited Prof. Tilo Pompe’s lab this week to learn from PhD student Veronika Riedl how soft hydrogel microparticles are produced. From left to right: Prof. Tilo Pompe, Dr. Benjamin Simona, Rebecca Graul and Veronika Riedl.
At the “Creative Day”, organized by the start-up initiative #SMILE and the #Research and Transfer Center for Bioactive Matter at Leipzig University, an interdisciplinary team used creativity techniques to develop inspiring product and business ideas. Our junior research group leader Dr. Henri Franquelim now wants to implement these with his team and bring them into the application.
Dr. Henri Franquelim discussing with participants. Photo: SMILE/ Gundula von Fintel Result
Researchers at Leipzig University have succeeded in moving tiny amounts of liquid at will by remotely heating water over a metal film with a laser. The currents generated in this way can be used to manipulate and even capture tiny objects. This will unlock groundbreaking new solutions for nanotechnology, the manipulation of liquids in systems in tiny spaces, or in the field of diagnostics, by making it possible to detect the smallest concentrations of substances with new types of sensor systems. In an article recently published in the high-impact journal “Nature Communications”, Martin Fränzl and Professor Frank Cichos of the Faculty of Physics and Earth Sciences at Leipzig University describe how this was achieved.
Although biodegradable plastic alternatives to PET are now available, they have so far represented a niche product. When it comes to requirements such as mechanical and thermal stability, use as a moisture barrier and durability, they can only be used to a limited extent for many applications. However, it is precisely these desired properties that make the ever-growing mountains of plastic waste and the associated environmental pollution one of the greatest challenges of our time. Therefore, in addition to strategies for plastic waste avoidance, recycling processes are becoming increasingly important. Scientists at the University of Leipzig have now developed a measuring method that is intended to accelerate the development of plastics that can be recycled several times. The results have now been published in the journal “ACS Catalysis”, one of the most renowned journals on the subject of biocatalysis/enzymes.
