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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 , Surface grafted N-Oxides have low-fouling and antibacterial properties(Wiley, 2023-12-13)Scopus© Citations 4 20 63 - 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 , Microorganisms harbor keys to a circular bioeconomy making them useful tools in fighting plastic pollution and rising CO2 levelsThe major global and man-made challenges of our time are the fossil fuel-driven climate change a global plastic pollution and rapidly emerging plant, human and animal infections. To meet the necessary global changes, a dramatic transformation must take place in science and society. This transformation will involve very intense and forward oriented industrial and basic research strongly focusing on (bio)technology and industrial bioprocesses developments towards engineering a zero-carbon sustainable bioeconomy. Within this transition microorganisms-and especially extremophiles-will play a significant and global role as technology drivers. They harbor the keys and blueprints to a sustainable biotechnology in their genomes. Within this article, we outline urgent and important areas of microbial research and technology advancements and that will ultimately make major contributions during the transition from a linear towards a circular bioeconomy.Publicationtype: Journal ArticleScopus© Citations 27 73 207 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Biocatalytic phosphorylations of metabolites: past, present, and futurePhosphorus is a key element for life that occurs in living cells as a structural part of many key biochemicals. Phosphorus plays important functional roles in biocatalysis, such as making metabolic reaction steps irreversible by transferring energy-rich groups, using phosphate groups as leaving groups, or selectively hydrolyzing phosphorus–oxygen or phosphorus–nitrogen bonds. The large number of biocatalysts known to catalyze the transfer of phosphorus-containing groups from donor molecules to acceptor molecules covers a wide variety of reaction classes. Bioprocessing technology can and should replicate these naturally occurring reactions. We illuminate some strategic advantages of this promising technology for developing biocatalytic processes and separation steps. Constraints, opportunities, and outlooks for implementing green engineering procedures to establish sustainable production processes are discussed.Publicationtype: Review Article173 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Bioreaction engineering leading to efficient synthesis of L-glyceraldehyd-3-phosphate(Wiley-VCH, 2016-12-19); ; ; ; Enantiopure L-glyceraldehyde-3-phosphate (L-GAP) is a useful building block in natural biological and synthetic processes. A biocatalytic process using glycerol kinase from Cellulomonas sp. (EC 2.7.1.30) catalyzed phosphorylation of L-glyceraldehyde (L-GA) by ATP is used for the synthesis of L-GAP. L-GAP has a half-life of 6.86 h under reaction conditions. The activity of this enzyme depends on the Mg2+ to ATP molar ratio showing maximum activity at the optimum molar ratio of 0.7. A kinetic model is developed and validated showing a 2D correlation of 99.9% between experimental and numerical data matrices. The enzyme exhibits inhibition by ADP, AMP, methylglyoxal and Ca2+, but not by L-GAP and inorganic orthophosphate. Moreover, equal amount of Ca2+ exerts a different degree of inhibition relative to the activity without the addition of Ca2+ depending on the Mg2+ to ATP molar ratio. If the Mg2+ to ATP molar ratio is set to be at the optimum value or less, inorganic hexametaphosphate (PPi6) suppresses the enzyme activity; otherwise PPi6 enhances the enzyme activity. Based on reaction engineering parameters such as conversion, selectivity and specific productivity, evaluation of different reactor types reveals that batchwise operation via stirred-tank reactor is the most efficient process for the synthesis of L-GAP.Publicationtype: Journal Article111 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Biocatalytic phosphorylation of metabolitesThis chapter focusses on selective biocatalytic phosphorylation reactions of metabolites. Phosphoryl group transfer reactions are of fundamental importance for living organisms and a variety of enzyme classes are involved in catalyzing these phosphorylation reactions. A large number of phosphorylases, phosphatases, and phosphotransferases/ kinases have been described as enzymes for the biocatalytic formation of new O-P- bonds, while the number of enzymes catalyzing the formation of N-P-, S-P-, and C-P-bonds is much smaller. Analytical method development, in particular separation and detection methodologies, for the direct analysis of biocatalytic phosphorylation reactions, are described as decisive steps for the assay and screening of novel phosphorylating biocatalysts, for investigating their functional properties and for process design. It is equally important for obtaining product stability data, as the areas of stability for the phosphorylated metabolites are best determined by experiments. As high-energy phosphate compounds are key players in life processes, the most important phosphate compounds are discussed in this chapter. Even though ATP is preferable in most enzymatic phosphorylation reactions, additional phosphoryl donors with varying energy level, availability, and specificity are of great interest. The stereo- and regioselectivity of phosphorylating enzymes offers benefits for the production of phosphate esters. A selection of new emerging phosphorylation reactions is shown. The subchapter on reaction engineering for biocatalytic phosphorylation processes provides basic reaction engineering principles, reaction kinetics, reaction system and process optimization strategies for biocatalytic phosphorylation reactions. The transition from stoichiometric phosphorylation reactions to biocatalytic phosphorylation reactions improves selectivity, safety, health, and environment, reduces the number of reaction steps in existing phosphoryla-tion routes, and decreases the waste-to-product ratio, if the phosphate donor is either recycled or used up in the reaction.Publicationtype: Book Part73 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , The Metagenome-derived enzymes LipS and LipT increase the diversity of known lipases(Public Library of Science (PLoS), 2012-10-24); ; ; ; Triacylglycerol lipases (EC 3.1.1.3) catalyze both hydrolysis and synthesis reactions with a broad spectrum of substrates rendering them especially suitable for many biotechnological applications. Most lipases used today originate from mesophilic organisms and are susceptible to thermal denaturation whereas only few possess high thermotolerance. Here, we report on the identification and characterization of two novel thermostable bacterial lipases identified by functional metagenomic screenings. Metagenomic libraries were constructed from enrichment cultures maintained at 65 to 75°C and screened resulting in the identification of initially 10 clones with lipolytic activities. Subsequently, two ORFs were identified encoding lipases, LipS and LipT. Comparative sequence analyses suggested that both enzymes are members of novel lipase families. LipS is a 30.2 kDa protein and revealed a half-life of 48 h at 70°C. The lipT gene encoded for a multimeric enzyme with a half-life of 3 h at 70°C. LipS had an optimum temperature at 70°C and LipT at 75°C. Both enzymes catalyzed hydrolysis of long-chain (C12 and C14) fatty acid esters and additionally hydrolyzed a number of industry-relevant substrates. LipS was highly specific for (R)-ibuprofen-phenyl ester with an enantiomeric excess (ee) of 99%. Furthermore, LipS was able to synthesize 1-propyl laurate and 1-tetradecyl myristate at 70°C with rates similar to those of the lipase CalB from Candida antarctica. LipS represents the first example of a thermostable metagenome-derived lipase with significant synthesis activities. Its X-ray structure was solved with a resolution of 1.99 Å revealing an unusually compact lid structure. © 2012 Chow et al.Publicationtype: Journal ArticleScopus© Citations 67 335 248