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Item type:Publication, Access status: with files , A combined chemo-enzymatic treatment for the oxidation of epoxy-based carbon fiber-reinforced polymers (CFRPs)(Frontiers Media S.A., 2025-10-31); ; ; Carbon fiber-reinforced polymers (CFRPs), particularly epoxy-based composites, have become essential in the aerospace, automotive, and wind energy industries due to their robust mechanical properties, and lightweight nature. However, there is a lack of recycling technologies that are environmentally sustainable while also ensuring the recovery of carbon fibers in their original state. Although certain bacterial and fungal strains can colonize epoxy polymers, enzymes capable of efficiently degrading these materials have not yet been reported. Consequently, there is an urgent need for an effective, sustainable, and biologically inspired solution for CFRP recycling. Here, a chemo-enzymatic two-step oxidation process was developed. A chemical pre-treatment with propionic acid and hydrogen peroxide was used to recover imbedded carbon fibers. Additionally, three novel bacterial laccases isolated from a European spruce bark beetle gut metagenome (Ips typographus) demonstrated the ability to oxidize three epoxy resin scaffolds derived from TGMDA-based epoxy resin system, a high-performance material commonly used in aerospace applications. The sequential combination of both oxidative steps enabled the retrieval of clean carbon fibers and showed the potential of the laccase to partially further modify the pre-treated cured epoxy. This bio-inspired approach marks an initial step toward developing a bio-based recycling method for epoxy CFRPs.Publicationtype: Journal Article57 15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , The 11th International Congress on Biocatalysis (biocat2024), Hamburg, Germany, 25-29 August 2024(Multidisciplinary Digital Publishing Institute (MDPI), 2025-06-10); ; ; ; The "11th International Congress on Biocatalysis (biocat2024)" was part of a biennial series that unites the fields of biology and chemistry, attracting researchers from the life sciences, engineering, and computer science. This international forum provides an opportunity for scientists worldwide to connect, seek collaboration for future projects, and gain insights into contemporary topics and innovative techniques. Biocat covers a range of compelling subjects and recent advancements in biocatalysis, including enzyme discovery, evolution, and applications. This congress focused on six key topics: AI and computational methods, structure–function analysis and enzyme engineering, enzymatic and whole-cell biotransformations, reaction cascades (electro-, chemo-, and photoenzymatic synergies), bioprocess engineering and the design of smart reactors, and facing climate change through sustainability and a circular bioeconomy. In 2024, we welcomed 344 expert delegates alongside 21 internal attendees, including 154 women and 1 non-binary participant, bringing the total number of participants to an impressive 365. Established researchers and emerging scientists from academia and industry delivered a total of 119 presentations, comprising 59 standard lectures, 60 lightning talks, and 195 posters. Six industry exhibitors showcased their latest products and services, providing an excellent opportunity to strengthen the connection between science and industry. Furthermore, the biocat award, recognized as one of the most prestigious honors in biotechnology, was presented for the eleventh time in the categories of "Science in Academia", "Lifetime Achievement" and "Industry".Publicationtype: Journal Article49 40 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , ProFA - Valorization of macroalgae biomass as source of proteins and formic acid(Royal Society of Chemistry (RSC), 2025-05-26); ; ; ; Macroalgae are promising feedstocks for the sustainable production of bioplastic films from proteins or platform chemicals such as formic acid (FA) as they are valuable sources of proteins and carbohydrates. This study explores the possibility of using macroalgae as biomass for biogenic FA production using the OxFA process in combination with the extraction of proteins from macroalgae with a focus on resource utilisation and innovation. Herein, the extraction of proteins and the utilisation of the other components of macroalgae to produce FA is linked for the first time. The aim was to find out which macroalgae is best suited to produce FA and protein-rich solids. For this purpose, three different algae were tested: The brown alga Fucus vesiculosus, the green alga Ulva fenestrata and the red alga Porphyra dioica. In addition, the most suitable catalyst for this study was selected from the two polyoxometalates H5PV2Mo10O40 (HPA-2) and H8PV5Mo7O40 (HPA-5) known for their suitability in the OxFA process. After Porphyra dioica proved to be a promising substrate, the parameters temperature (80 °C – 120 °C), reaction time (18 h – 30 h) and catalyst/substrate ratio (0.05 to 0.5) were evaluated for their statistical influence using a Box-Behnken design of experiments. The resulting model was then used to optimise the protein content and FA yield. The optimal conditions were determined to 80 °C, 30 hours and a catalystto-substrate ratio of 0.5 resulting in a protein yield of 59.5 % and a formic acid yield of 16.4 %. For protein extraction from the solid residues, three different methods such as alkaline hydrolysis, ultrasound-assisted extraction (UAE) and ionic liquid extraction (ILE) were investigated. All extraction methods resulted in a protein recovery of more than 40 %dw, with UAE yielding the highest protein recovery of 87.2 %dw (at 100 % sonication amplitude) showing 30 % higher protein recovery than alkaline hydrolysis and 40 % higher protein recovery than ILE. It turned out that the OxFA process followed by protein extraction using UAE gave a high protein recovery and a promising yield of formic acid.Publicationtype: Journal Article45 47 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , From waste to value: extraction of protease enzymes from Brewer’s spent yeast(Multidisciplinary Digital Publishing Institute (MDPI), 2025-02-05); ; ; ; This study investigates the potential of additive-free extraction techniques to produce a proteolytically active yeast extract for use in the food industry. Brewer’s spent yeast, a by-product of the brewing industry, is utilized as a feedstock, and thus a new route for its valorization is proposed. Four methods of releasing these components while maintaining their intrinsic bioactivity are investigated: thermal autolysis, ultrasonication, cell milling and high-pressure homogenization. Thermal yeast autolysis resulted in the highest release of protease activity, with 2.45 ± 0.05 U/g<sub>dm</sub> after 3 h incubation at 45 °C. However, autolysis poses challenges for automation, and thus a stop criterion, due to the lack of in-line enzyme activity assays,. While glass bead treatment gave the highest reproducibility, ultrasonication and high-pressure homogenization resulted in comparably high protease activities in the BSY extracts produced. Both methods, in the form of a cell mill and high-pressure homogenizer, are cell disruption methods that are already employed on an industrial scale. It has now been demonstrated that these methods can be used to produce proteolytically active yeast extracts from a previously considered waste stream.Publicationtype: Journal Article42 34 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Macroalgae valorization for the production of polymers, chemicals, and energy(Elsevier, 2024-04-01); ; ; ; The increasing awareness of man-made environmental impact of our modern highly industrialized societies has led to an increasing demand of natural products representing additionally a key element within the transition towards a circular bioeconomy. In this sense, macroalgae constitute a renewable and abundant natural resource with high usage potentials in a wide range of very diverse applications. In addition to the respective useable bioactive compounds varying between species and more significantly between the three taxonomic groups, macroalgae are characterized by additional promising properties such as high growth rates, simple cultivation and harvesting strategies, and no competition with fertile lands. These are only some reasons why macroalgae have been used for centuries as a raw material in very different application fields; the food sector is only one prominent example. Furthermore, new macroalgae-based products have been developed over the last decades; this is true for hydrocolloids, nutra- and pharmaceuticals as well as biomaterials. Additionally, nowadays macroalgae are also a potential feedstock for green energy production in the form of gaseous and liquid biofuels such as biogas, bio-oil, or bioethanol. Within this context this review provides an analysis of the main compounds with possible economic potential obtained from green, red, and brown macroalgae as well as an evaluation of the global macroalgae market and the existing obstacles. Additionally, it also provides an overview of the macroalgae potential in new applications and as a source of green energy.Publicationtype: Review ArticleScopus© Citations 1 40 209 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Enzyme KineticsIn this chapter, you will learn the fundamental concepts of chemical and enzyme catalysis as well as kinetics such as the lock and key and the induced-fit models, the idea of an enzyme-substrate complex, the Michaelis-Menten equation, or the steady-state assumption. Key basic concepts such as catalysts and their classification, reaction rate, enzyme inhibition, and the order of a reaction are also explained. A fundamental point to evaluate enzyme-catalyzed reactions is the determination of kinetic parameters such as the Michaelis-Menten constant and the maximum reaction rate. Their calculation using linearization, numeric, and combined methods is explained in this chapter. Here you will also find the necessary equations and models to determine other relevant parameters such as the turnover frequency and the specificity constant.Publicationtype: Book Part17 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Enzyme-assisted extraction of ulvan from the Green Macroalgae ulva fenestrata(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-23); ; ; Ulvan is a sulfated polysaccharide extracted from green macroalgae with unique structural and compositional properties. Due to its biocompatibility, biodegradability, and film-forming properties, as well as high stability, ulvan has shown promising potential as an ingredient of biopolymer films such as sustainable and readily biodegradable biomaterials that could replace petroleum-based plastics in diverse applications such as packaging. This work investigates the potential of Ulva fenestrata as a source of ulvan. Enzyme-assisted extraction with commercial cellulases (Viscozyme L and Cellulysin) and proteases (Neutrase 0.8L and Flavourzyme) was used for cell wall disruption, and the effect of the extraction time (3, 6, 17, and 20 h) on the ulvan yield and its main characteristics (molecular weight, functional groups, purity, and antioxidant capacity) were investigated. Furthermore, a combined process based on enzymatic and ultrasound extraction was performed. Results showed that higher extraction times led to higher ulvan yields, reaching a maximum of 14.1% dw with Cellulysin after 20 h. The combination of enzymatic and ultrasound-assisted extraction resulted in the highest ulvan extraction (17.9% dw). The relatively high protein content in U. fenestrata (19.8% dw) makes the residual biomass, after ulvan extraction, a potential protein source in food and feed applications.Publicationtype: Journal ArticleScopus© Citations 2 32 109 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Towards sustainable recycling of epoxy-based polymers : approaches and challenges of epoxy biodegradation(Multidisciplinary Digital Publishing Institute (MDPI), 2023-06-12); ; ; Epoxy resins are highly valued for their remarkable mechanical and chemical properties and are extensively used in various applications such as coatings, adhesives, and fiber-reinforced composites in lightweight construction. Composites are especially important for the development and implementation of sustainable technologies such as wind power, energy-efficient aircrafts, and electric cars. Despite their advantages, their non-biodegradability raises challenges for the recycling of polymer and composites in particular. Conventional methods employed for epoxy recycling are characterized by their high energy consumption and the utilization of toxic chemicals, rendering them rather unsustainable. Recent progress has been made in the field of plastic biodegradation, which is considered more sustainable than energy-intensive mechanical or thermal recycling methods. However, the current successful approaches in plastic biodegradation are predominantly focused on polyester-based polymers, leaving more recalcitrant plastics underrepresented in this area of research. Epoxy polymers, characterized by their strong cross-linking and predominantly ether-based backbone, exhibit a highly rigid and durable structure, placing them within this category. Therefore, the objective of this review paper is to examine the various approaches that have been employed for the biodegradation of epoxy so far. Additionally, the paper sheds light on the analytical techniques utilized in the development of these recycling methods. Moreover, the review addresses the challenges and opportunities entailed in epoxy recycling through bio-based approaches.Publicationtype: Journal ArticleScopus© Citations 7 60 126 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Enzyme-assisted extraction of alginate from beach wrack fucus vesiculosus(Wiley-VCH, 2023-01-11); ; ; ; Beach wrack constitutes an unutilized, abundant renewable source of marine macro algae being rich in valuable biopolymers. This work investigates the revalorization of the brown algae Fucus vesiculosus collected from beach wrack as a source of alginate, the main polysaccharide in brown algae which constitutes a potential ingredient for the development of biopolymer films. Enzyme-assisted extraction has been investigated for cell disruption with commercial cellulase blends and proteases. The effect of enzyme type, enzyme activity, and extraction time on alginate yields, molecular weight distribution, functional groups, and purity has been studied.Publicationtype: Journal ArticleScopus© Citations 3 75 297 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Influence of industrial olive mill wastewater pre-Treatment on the Scenedesmus obliquus growth(2022-10); ; ; Industrial olive mill wastewater (OMW) is one of the more problematic wastewaters to treat by the conventional biological process since it has a high organic load expressed as high values for chemical oxygen demand (COD) and total organic carbon (TOC). In addition, to other inhibitory compounds such as phenolic compounds. High values for maximum specific growth rate and volumetric biomass productivity are mandatory to success in the industrial microalgal culture. In this work, three operating units, flocculation, artificial photolysis, and microfiltration before the microalga Scenedesmus obliquus culture were established. All experiments were carried out on a laboratory scale in stirred batch tank photobioreactors using different dilutions of OMW as culture medium (5% to 100% of OMW, v/v). The highest value of the maximum specific growth rate for Scenedesmus obliquus, ?m=0.0836 h1, was determined in the culture medium at 100% of OMW. However, at the lowest concentration of OMW, 5% of OMW (v/v), in the culture medium was determined the highest biomass productivity, 0.587, mg/(Lh). Regarding the treated water quality, the COD removal (93.7%) was registered during the application of the pre-Treatment units plus algal culture when 100% of OMW was used. The resulting treated water can be reused in irrigation.Publicationtype: Conference Paper31