Efficient and durable biocatalysts are important for sustainable CO2capture technologies, but enzyme stability often limits their use under harsh process conditions. Here, we evaluate carbonic anhydrases (CAs) adsorbed onto aminated mesoporous SBA-15 as biocatalysts for CO2capture under the hypothesis of adsorption-induced thermal stabilization. Carbonic anhydrase from the thermophilic bacterium Persephonella marina (pmCA) and commercial bovine erythrocyte carbonic anhydrase (bCA) were used. Enzyme adsorption isotherms for pmCA and bCA onto the aminated SBA-15 were established, along with desorption tests. Adsorbed and free pmCA and bCA were incubated at 40–90 °C for 14 d. The structural integrity and possibility of amine leaching of the incubated (90°, 14 d) aminated SBA-15 were analyzed by X-ray diffraction (XRD) and NMR spectroscopy. The reaction product speciation in CO2-loaded catalyzed and uncatalyzed dispersions was monitored using infrared (IR) spectroscopy. The maximum enzyme adsorption capacities were established to be 1.4 ± 0.2 g pmCA·g-aminated SBA-15–1and 2.1 ± 0.5 g bCA·g-aminated SBA-15–1, with no detectable desorption. Adsorbed pmCA and bCA maintained high activity for 14 d at 40–65 °C and for 4 d at 90 °C, whereas free enzymes lost activity within 4 d at all temperatures. The XRD patterns of the heat-treated (90 °C, 14 d) aminated SBA-15 indicated a full collapse of the mesostructure. IR spectroscopy confirmed enhanced HCO3–formation in the presence of immobilized CA. Overall, enzyme adsorption onto the aminated SBA-15 significantly improved the thermal stability and activity of pmCA and bCA compared to the free enzymes, demonstrating the potential of adsorbed CAs for biocatalysis.

Amine transaminases (ATAs), belonging to the class III transaminases within the superfamily of pyridoxal-5 '-phosphate-dependent enzymes, catalyze transamination reactions between amino donors and amino acceptors. These enzymes are particularly appealing for their role in stereospecific synthesis of chiral amines. However, the stability of most ATAs is not satisfying, limiting their suitability for industrial applications. Among them, the amine transaminase from Silicibacter pomeroyi (Sp-ATA) has drawn attention due to its high activity and broad substrate scope under mild conditions and high pH. Nevertheless, maintaining the activity at higher temperatures is a challenge. Previous studies to enhance enzyme function through directed evolution have shown promising results, yet predicting the cooperative effects of individual stabilizing mutations remains challenging. An alternative strategy is ancestral sequence reconstruction (ASR), which is based on gene sequences to create a more or less artificial phylogenetic tree. This study aims to leverage ASR techniques to explore the thermostability, solvent tolerance, and substrate profile of Sp-ATA, to find more stable transaminases. By using Sp-ATA as a template and incorporating insights from ancestral sequences, this strategy offers a promising approach for developing robust biocatalysts suitable for industrial applications.

Protein-based absorbent materials exhibit significant limitations in water retention compared to synthetic superabsorbent polymers (SAPs), widely used in agriculture, hygiene, and biomedical applications. Recent investigations have focused on leveraging highly soluble charged proteins such as patatin (a glycoprotein derived from potatoes) as natural alternatives to synthetic SAPs, given their unique structural properties and the opportunity they provide as sustainable raw material alternatives. This study investigates how the intrinsic amino acid composition and charged residues of patatin can be modified through mutagenesis to tailor its superabsorbent properties. Here, patatin was expressed in Escherichia coli to improve the water absorption capacity by altering its amino acid composition. By increasing liquid accessibility and charge density, our method of altering the charged profile of the protein significantly enhances the protein's swelling capacity, doubling its absorption compared to native patatin. Additionally, molecular dynamics simulations reveal that protein variants enriched with lysine and aspartic acid facilitate increased hydrogen bonding interactions with water molecules, thereby enhancing hydration. These results provide a fundamental understanding of how to tailor the physicochemical nature of proteins to develop them as viable bio-based absorbents for advanced sanitary applications, combining material science and biotechnology.

Building blocks with amine functionality are crucial in the chemical industry. Biocatalytic syntheses and chemicals derived from renewable resources are increasingly desired to achieve sustainable production of these amines. As a result, renewable materials such as furfurals, especially furfurylamines like 5-(hydroxymethyl)furfurylamine (HMFA) and 2,5-di(aminomethyl)furan (DAF), are gaining increasing attention. In this study, we identified four different amine transaminases (ATAs) that catalyze the reductive amination of 5-(hydroxymethyl)furfural (HMF) and 2,5-diformylfuran (DFF). We successfully immobilized these ATAs on glutaraldehyde-functionalized amine beads using multiple binding and on amine beads by site-selective binding of the unique Ca-formylglycine within an aldehyde tag. All immobilized ATAs were efficiently reused in five repetitive cycles of reductive amination of HMF with alanine as co-substrate, while the ATA from Silicibacter pomeroyi (ATA-Spo) also exhibited high stability for reuse when isopropylamine was used as an amine donor. Additionally, immobilized ATA-Spo yielded high conversion in the batch syntheses of HMFA and DAF using alanine (87% and 87%, respectively) or isopropylamine (99% and 98%, respectively) as amine donors. We further demonstrated that ATA-Spo was effective for the reductive amination of HMF with alanine or isopropylamine in continuous-flow catalysis with high conversion up to 12 days (48% and 41%, respectively).

This work spotlights the experiences from ten years of implementing sustainable development in all educational programs at a technical university. With a focus on the critical issue of involving more academics in the work, experiences are shared through an ethnographic account including focus group interviews. "€˜Sustainable development"€™ has been perceived as both superficial and overwhelming; unclear yet somehow predetermined; it has been perceived to demand non-existent space in the curriculum; and it has challenged the academics regardless of the subjects'€™ relatedness to sustainability. It is concluded that the evolution of a web of interconnected people, key academics, activities, norms and tools has contributed to an increased participation. The work for authenticity, reliability and feasibility, along with institution-wide and long-term academic development tools is presented.

ATAs engineered for having an enlarged small binding pocket were applied for the synthesis of enantiomerically pure (R)-benzo[1,3]dioxol-5-yl-butylamine, a chiral component of human leukocyte elastase inhibitor DMP 777 (L-694,458). Kinetic resolution of the racemic amine was performed by using the L59A variant of the (S)-selective ATA from Chromobacterium violaceum (Cv-ATA), providing the residual (R)-enantiomer in excellent yield and >99% ee. At moderate enzyme loading and absence of co-solvent, high volumetric productivity of 0.22 mol L−1 h−1 (42.5 g L−1 h−1) was achieved. Complementarily, the (S)-enantiomer was generated via kinetic resolution using the (R)-selective ATA-117-Rd11 from Arthrobacter sp. with acetone as the amino acceptor. In an alternative approach, we employed ATA-117-Rd11 for the asymmetric amination of the prochiral ketone precursor, which at 86% conversion gave the (R)-benzo[1,3]dioxol-5-yl-butylamine with excellent >99% ee. We further evaluated the utility of Cv-ATA L59A for the asymmetric synthesis of pharmaceutically relevant (S)-1-phenylbutan-1-amine, a chiral component of the deubiquitinase inhibitor degrasyn (WP1130). The enzyme showed good tolerance to high concentrations of isopropylamine, producing (S)-1-phenylbutan-1-amine in enantiomerically pure form (>99% ee).

Mucus is a self-healing gel that lubricates the moist epithelium and provides protection against viruses by binding to viruses smaller than the gel’s mesh size and removing them from the mucosal surface by active mucus turnover. As the primary nonaqueous components of mucus (≈0.2%–5%, wt/v), mucins are critical to this function because the dense arrangement of mucin glycans allows multivalence of binding. Following nature’s example, bovine submaxillary mucins (BSMs) are assembled into “mucus-like” gels (5%, wt/v) by dynamic covalent crosslinking reactions. The gels exhibit transient liquefaction under high shear strain and immediate self-healing behavior. This study shows that these material properties are essential to provide lubricity. The gels efficiently reduce human immunodeficiency virus type 1 (HIV-1) and genital herpes virus type 2 (HSV-2) infectivity for various types of cells. In contrast, simple mucin solutions, which lack the structural makeup, inhibit HIV-1 significantly less and do not inhibit HSV-2. Mechanistically, the prophylaxis of HIV-1 infection by BSM gels is found to be that the gels trap HIV-1 by binding to the envelope glycoprotein gp120 and suppress cytokine production during viral exposure. Therefore, the authors believe the gels are promising for further development as personal lubricants that can limit viral transmission.

Transaminases are pyridoxal 5’-phosphate (PLP)-dependent enzymes that transfer amino-functions. The transaminase from Silicibacter pomeroyi (SpATA) exhibits a broad substrate spectrum. In this work we examined the effect of different conditions (light, buffer and PLP-concentration) on the stability of SpATA, as well as the causes for these effects. The enzyme was stored either in TRIS or CHES with 0–10 mM added PLP at 22 °C. The samples were either kept dark or they were exposed to light. The results show that invariably, all samples kept in darkness exhibited longer half-life times than the ones exposed to light. An increase in the half-life from 8 h to 720 h could be achieved solely by keeping the sample dark. Especially samples in CHES buffer inactivated faster in light the more PLP was present, due to the degradation of PLP. In TRIS however, an imine-bond between TRIS and PLP protects PLP from degradation.

KTH, as most universities, is going through major transformations to respond to the challenges in society. In this contribution, we present ten years of development work that has aimed to enable strengthened participation in educational change, across KTH's organizational boundaries-among teachers, students, and administrative staff. A practitioner and action-oriented approach has guided the development work, from 2011 to today, in creating new meeting arenas. The pandemic outbreak and the associated paralysis of our normal activities proved to lead to an increased importance of the established arenas for educational issues. A broadening could be seen in participating actors and a significant increase in the number of participants. We conclude with emphasizing the value we see with organizing for participation in the transformation of higher education.