Formation of self-assembled fibril aggregates of trypsin-controllably hydrolyzed soy protein and its regulation on stability of high internal phase Pickering emulsions.

The mechanisms of trypsin hydrolysis time on the structure of soy protein hydrolysate fibril aggregates (SPHFAs) and the stability of SPHFAs-high internal phase Pickering emulsions (HIPPEs) were investigated. SPHFAs were prepared using soy protein hydrolysate (SPH) with different trypsin hydrolysis time (0 min-120 min) to stabilize SPHFAs-HIPPEs. The results showed that moderate trypsin hydrolysis (30 min, hydrolysis degree of 2.31 %) induced SPH unfolding and increased the surface hydrophobicity of SPH, thereby promoting the formation of flexible SPHFAs with maximal thioflavin T intensity and ζ-potential. Moreover, moderate trypsin hydrolysis improved the viscoelasticity of SPHFAs-HIPPEs, and SPHFAs-HIPPEs remained stable after storage at 25 °C for 80 d and heating at 100 °C for 1 h. Excessive trypsin hydrolysis (> 30 min) decreased the stability of SPHFAs-HIPPEs. In conclusion, moderate trypsin hydrolysis promoted the formation of flexible SPHFAs with high surface charge by inducing SPH unfolding, thereby promoting the stability of SPHFAs-HIPPEs.

High-yield production of completely linear dextrans and isomalto-oligosaccharides by a truncated dextransucrase from Ligilactobacillus animalis TMW 1.971.

Several lactic acid bacteria are capable of producing water-soluble exopolysaccharides such as dextran from sucrose by using glucansucrases. Several recombinant glucansucrases were described, however, yields were often limited and most dextrans were branched at position O3. In this study, the dextransucrase from Ligilactobacillus animalis TMW 1.971 was recombinantly produced without its N-terminal variable region and used for dextran synthesis. The enzyme expressed well and showed very high total as well as transferase activities compared to other glucansucrases. It was able to transfer nearly all glucose from sucrose to oligo- and polymeric products under certain conditions (about 95 % of glucose transferred). The high efficiency of the enzyme made it possible to obtain absolute dextran yields of up to 214.9 g/L from a 1.5 M sucrose solution. Structural characterization of the products showed that the dextrans produced have a rather low molecular weight, a narrow size distribution, and are completely linear. Furthermore, we showed that various low molecular weight dextrans or 1,6-linked isomalto-oligosaccharides can be efficiently produced by acid hydrolysis. Overall, we demonstrated that Ligilactobacillus animalis TMW 1.971 dextransucrase can be used to efficiently synthesize dextrans with a quite unique structural composition. The dextrans produced have a high potential for further applications such as synthesis of copolymers or size standards with a very defined molecular structure.

Colloidal platinum nanoparticles enhance resin-dentin bonding durability.

OBJECTIVES: This study aims to investigate the effect of colloidal platinum nanoparticles (CPN) on the durability of resin-dentin bonding performance with contemporary adhesives. METHODS: Sixty non-carious human maxillary premolars were subjected to microtensile bond strength (µTBS) testing and divided into two main groups: CPN-treated and untreated. Within each group, specimens were randomly allocated to Clearfil Megabond 2 (MB2), Scotchbond Universal Plus Adhesive with self-etch mode (SE-SUP), and etch-and-rinse mode (ER-SUP) subgroups (n = 10/group). CPN was applied to dentin in the MB2 and SE-SUP groups for 20 s, followed by rinsing before adhesive application. In the ER-SUP group, CPN was applied after etch-and-rinse. The µTBS was tested after 24 h, 6 months, and 1 year, and the fracture modes were observed using SEM. The µTBS data were analyzed using a two-way ANOVA and post-hoc Tukey HSD test (α = 0.05). An additional twelve premolars underwent TEM/STEM/EDX for ultra-morphological observations. RESULTS: The application of CPN significantly prevented a decline in the µTBS of both the MB2 and SE-SUP groups. No significant decrease was observed in the ER-SUP group, either with aging or CPN application. Ultra-morphological images revealed platinum nanoparticles attaching to the collagen fibrils of the hybrid layer regardless of aging. It was highlighted that the nanoparticles attached to the banded collagen in the aging groups were observed. SIGNIFICANCE: CPN exhibits the potential in enhancing the longevity of resin-dentin bonding in SE mode.

Structure, antioxidant activity, and neuroprotective effect of black soybean (Glycine max (L.) merr.) protein hydrolysates.

The potential biological properties of protein hydrolysates have generated considerable research interest. This study was to hydrolyze black soybean protein (BSP) using five different commercial enzymes, and elucidate the influence of these enzymes on the structure and biological activities of the resulting hydrolysates. Enzymatic treatment changed secondary and tertiary structures of BSP, decreased particle size, α-helix and ß-sheet. Alcalase hydrolysate had the highest hydrolytic degree (29.84 %), absolute zeta potential (38.43 mV), the smallest particle (149.87 nm) and molecular weight (<3 kDa). In silico revealed alcalase hydrolysate had the strongest antioxidant potential. This finding was further validated through the lowest IC50 (mg/mL) in DPPH (2.67), ABTS (0.82), Fe2+ chelating (1.33) and·OH (1.12). Moreover, cellular antioxidant assays showed alcalase hydrolysate had the strongest cytoprotective effects on H2O2-induced PC12 cells. These results suggest BSPEHs, especially those prepared by alcalase, have potential as bioactive ingredients for nutrition, healthcare and food industry.

The Effects of an Oral Supplementation of a Natural Keratin Hydrolysate on Skin Aging: A Randomized, Double-Blind, Placebo-Controlled Clinical Study in Healthy Women.

BACKGROUND: Keratin hydrolysates are active components used in food supplements to alleviate aging signs on skin, hair, and nails. AIMS: This randomized, double-blind, placebo-controlled study evaluates a novel keratin hydrolysate obtained from poultry feathers. This feather keratin hydrolysate (FKH) results in a characteristic mix of free L-amino acids (≥ 83.5%). FKH was administered as a food supplement to a panel of adult women showing aging physiological signs. METHODS: Participants were randomly assigned in three groups to receive daily dosages of 500 or 1000 mg of FKH or placebo for 90 days. Parameters of skin roughness, wrinkle features, deep skin moisturization, skin maximum elongation and elasticity, skin thickness, skin anisotropy, skin density, gloss of skin, hair and nails, and nail hardness were evaluated. Subjects also answered a questionnaire related to the treatment efficacy perception. RESULTS: Both FKH treatments showed a significant improvement of all parameters compared to day 0 and to placebo, with an exception for fiber anisotropy and fiber density which showed a significant improvement compared to day 0 and a tendency to improve compared to placebo. These measurements were bolstered by the results of a self-assessment questionnaire, showing an overall set of positive answers for both treatments compared to placebo. CONCLUSIONS: Oral supplementation of FKH for 90 days is associated with an improvement in the appearance of facial skin, hair, and nails. This study highlights the benefits of free L-amino acids mix as potential aminobiotics and not just as building blocks of proteins, suggesting a new perspective of nutricosmetic food.

Development of poly(butylene oxalate-co-furanoate) copolymers with enhanced sustainability and hydrolytic degradability.

Polyoxalate, a novel intrinsically hydrolysable polyester, garners significant interest for its high cost-effectiveness and versatility. However, concerns persist regarding its durability in practical applications. This study integrates bio-based poly(butylene furanoate) (PBF), which possesses remarkable barrier performance, into the poly(butylene oxalate) (PBOx) framework to synthesize poly(butylene oxalate­co­furanoate) (PBOF) with tunable degradation rates. The influence of incorporating BF units on thermal, crystalline, mechanical, and barrier properties was systematically analyzed. Results demonstrated the addition of BF units dramatically improved the balance between degradation and physical properties. Laboratory degradation experiments indicated that PBOF possessed significant degradation effects. Among them, PBOF-41 (with 41 % molar furanoate) decreased in weight by 20 % in freshwater, 70 % in an enzyme solution, and 8 % in artificial seawater within 30 days. After 28 days of degradation in soil, the residual weight was reduced to 80 % of its initial weight. Theoretical calculations and experiments have clarified the enhancement of the Gibbs free energy and energy barrier of the hydrolysis reaction by the BF unit. In summary, PBOF copolyesters have excellent gas barrier performance, adjustable thermal properties, well-balanced mechanical properties, and degradability, making them highly promising for sustainable plastic products.

DNA Nanotechnology for Application in Targeted Protein Degradation.

DNA is a kind of flexible and versatile biomaterial for constructing nanostructures and nanodevices. Due to high biocompatibility and programmability and easy modification and fabrication, DNA nanotechnology has emerged as a powerful tool for application in intracellular targeted protein degradation. In this review, we summarize the recent advances in the design and mechanism of targeted protein degradation technologies such as protein hydrolysis targeted chimeras, lysosomal targeted chimeras, and autophagy based protein degradation. Subsequently, we introduce the DNA nanotechnologies of DNA cascade circuits, DNA nanostructures, and dynamic machines. Moreover, we present the latest developments in DNA nanotechnologies in targeted protein degradation. Finally, the vision and challenges are discussed.

Integrative approach to assessing bioactivity from hempseed protein isolate extracted and dehydrated by different methods: Synergising in silico prediction and in vitro validation.

This study demonstrated a comprehensive workflow combining in silico screening and prediction with in vitro validation to investigate the bioactivity of hempseed protein isolate (HPI) extracted and dehydrated using different methods. By adopting an in silico approach, 13 major proteins of HPI were hydrolysed by 20 selected enzymes, leading to the prediction of 20 potential bioactivities. With papain hydrolysis, dipeptidyl peptidase-IV (DPP4) and angiotensin-converting enzyme (ACE) inhibitory activities emerged as having the highest potential. In vitro experiments confirmed these predictions, with DPP4 and ACE inhibitory activities displaying IC50 values of 0.32-0.42 mg/mL and 6.8-9.17 µg/mL, respectively. A strong correlation (r2 = 0.96) was observed between in vitro protein inhibitory results and in silico predicted data. This study demonstrated an effective integrative approach for predicting bioactive peptides in food protein, providing valuable guidance on its processing to create value-added products.

Recombinant production of Paenibacillus wynnii ß-galactosidase with Komagataella phaffii.

BACKGROUND: The ß-galactosidase from Paenibacillus wynnii (ß-gal-Pw) is a promising candidate for lactose hydrolysis in milk and dairy products, as it has a higher affinity for the substrate lactose (low KM value) compared to industrially used ß-galactosidases and is not inhibited by the hydrolysis-generated product D-galactose. However, ß-gal-Pw must firstly be produced cost-effectively for any potential industrial application. Accordingly, the yeast Komagataella phaffii was chosen to investigate its feasibility to recombinantly produce ß-gal-Pw since it is approved for the regulated production of food enzymes. The aim of this study was to find the most suitable way to produce the ß-gal-Pw in K. phaffii either extracellularly or intracellularly. RESULTS: Firstly, 11 different signal peptides were tested for extracellular production of ß-gal-Pw by K. phaffii under the control of the constitutive GAP promoter. None of the signal peptides resulted in a secretion of ß-gal-Pw, indicating problems within the secretory pathway of this enzyme. Therefore, intracellular ß-gal-Pw production was investigated using the GAP or methanol-inducible AOX1 promoter. A four-fold higher volumetric ß-galactosidase activity of 7537 ± 66 µkatoNPGal/Lculture was achieved by the K. phaffii clone 27 using the AOX1 promoter in fed-batch bioreactor cultivations, compared to the clone 5 using the GAP promoter. However, a two-fold higher specific productivity of 3.14 ± 0.05 µkatoNPGal/gDCW/h was achieved when using the GAP promoter for ß-gal-Pw production compared to the AOX1 promoter. After partial purification, a ß-gal-Pw enzyme preparation with a total ß-galactosidase activity of 3082 ± 98 µkatoNPGal was obtained from 1 L of recombinant K. phaffii culture (using AOX1 promoter). CONCLUSION: This study showed that the ß-gal-Pw was produced intracellularly by K. phaffii, but the secretion was not achieved with the signal peptides chosen. Nevertheless, a straightforward approach to improve the intracellular ß-gal-Pw production with K. phaffii by using either the GAP or AOX1 promoter in bioreactor cultivations was demonstrated, offering insights into alternative production methods for this enzyme.

Enzymatic hydrolysis pretreatment combined with glycosylation for soybean protein isolate applying in dual-protein yogurt.

This research investigated the viability of replacing milk protein with glycosylated soybean protein isolate (SPI) treated with different enzymatic hydrolysis times (0, 10, 20, 30, 40, and 50 min) in yogurt. The results showed that enzymatic hydrolysis pretreatment combined with glycosylation for SPI exhibited elevated grafting and solubility. Additionally, the high solubility of SPI (94.77 %) at 40 min facilitates the preparation of dual-protein yogurt (DPY). Compared to ESPI0-G, DPY that incorporates ESPI40-G through partial substitution of milk protein is capable of forming a denser and more stable gel matrix. Especially, the syneresis of DPY40 was reduced by 7.61 % compared to DPY0, which more closely approximates the texture properties of traditional yogurt. Meanwhile, glycosylated SPI treated with enzymatic hydrolysis can effectively degrade the beany flavor and slightly bitter taste in DPY. This study could provide a solid theoretical basis for the broader application and industrialization of plant-based yogurt.

Toward High-Energy-Density Aqueous Zinc-Iodine Batteries: Multielectron Pathways.

Aqueous zinc-iodine batteries (ZIBs) based on the reversible conversion between various iodine species have garnered global attention due to their advantages of fast redox kinetics, good reversibility, and multielectron conversion feasibility. Although significant progress has been achieved in ZIBs with the two-electron I-/I2 pathway (2eZIBs), their relatively low energy density has hindered practical application. Recently, ZIBs with four-electron I-/I2/I+ electrochemistry (4eZIBs) have shown a significant improvement in energy density. Nonetheless, the practical use of 4eZIBs is challenged by poor redox reversibility due to polyiodide shuttling during I-/I2 conversion and I+ hydrolysis during I2/I+ conversion. In this Review, we thoroughly summarize the fundamental understanding of two ZIBs, including reaction mechanisms, limitations, and improvement strategies. Importantly, we provide an intuitive evaluation on the energy density of ZIBs to assess their practical potential and highlight the critical impacts of the Zn utilization rate. Finally, we emphasize the cost issues associated with iodine electrodes and propose potential closed-loop recycling routes for sustainable energy storage with ZIBs. These findings aim to motivate the practical application of advanced ZIBs and promote sustainable global energy storage.

Bioprocess to produce biostimulants/biofertilizers based on microalgae grown using piggery wastewater as nutrient source.

In the present work, two downstream processes - high-pressure homogenization at 100 (HPH-100) and 1200 bar (HPH-1200), and enzymatic hydrolysis (EH) - were tested to produce biostimulant extracts from Tetradesmus obliquus grown in piggery wastewater at two concentrations (12.8 and 88.3 g/L). Extracts before and after centrifugation (C) were evaluated in four bioassays using garden cress (germination), mung bean (auxin-like activity), and cucumber (auxin- and cytokinin-like activity) relative to distilled water. The initial microalgal culture, without any treatment, had the best germination results (162 % at 0.2 g/L) and the only one that showed cytokinin-like activity (141 % at 0.5 g/L). In both auxin-like bioassays, the HPH-1200 + C and EH + C originated high values (186 and 155 % for cucumber, 290 and 285 % for mung bean, respectively). For mung bean, the HPH-1200 achieved the highest auxin-like effect (378 %). Finally, the extracted biomass contained essential nutrients for biofertilization, complementing the biostimulant extracts for sustainable agriculture application.

Hybrid Protocells Based on Coacervate-Templated Fatty Acid Vesicles Combine Improved Membrane Stability with Functional Interior Protocytoplasm.

Prebiotically-plausible compartmentalization mechanisms include membrane vesicles formed by amphiphile self-assembly and coacervate droplets formed by liquid-liquid phase separation. Both types of structures form spontaneously and can be related to cellular compartmentalization motifs in today's living cells. As prebiotic compartments, they have complementary capabilities, with coacervates offering excellent solute accumulation and membranes providing superior boundaries. Herein, protocell models constructed by spontaneous encapsulation of coacervate droplets by mixed fatty acid/phospholipid and by purely fatty acid membranes are described. Coacervate-supported membranes form over a range of coacervate and lipid compositions, with membrane properties impacted by charge-charge interactions between coacervates and membranes. Vesicles formed by coacervate-templated membrane assembly exhibit profoundly different permeability than traditional fatty acid or blended fatty acid/phospholipid membranes without a coacervate interior, particularly in the presence of magnesium ions (Mg2+). While fatty acid and blended membrane vesicles are disrupted by the addition of Mg2+, the corresponding coacervate-supported membranes remain intact and impermeable to externally-added solutes. With the more robust membrane, fluorescein diacetate (FDA) hydrolysis, which is commonly used for cell viability assays, can be performed inside the protocell model due to the simple diffusion of FDA and then following with the coacervate-mediated abiotic hydrolysis to fluorescein.

Deciphering the role of SAMHD1 in endometrial cancer progression.

BACKGROUND: Endometrial cancer (EC) presents significant clinical challenges due to its heterogeneity and complex pathophysiology. SAMHD1, known for its role as a deoxynucleotide triphosphate triphosphohydrolase, has been implicated in the progression of various cancers, including EC. This study focuses on elucidating the role of SAMHD1 in EC through its impact on TRIM27-mediated PTEN ubiquitination. RESULTS: Utilizing a combination of bioinformatics and cellular biology techniques, we investigated the interactions among SAMHD1, TRIM27, and PTEN. Our findings reveal that SAMHD1 modulates PTEN ubiquitination via TRIM27, impacting key pathways involved in EC pathogenesis. These interactions suggest a critical mechanism by which SAMHD1 could influence tumor behavior and progression in EC. CONCLUSIONS: The results from this study underscore the potential of targeting the SAMHD1-TRIM27-PTEN axis as a therapeutic strategy in EC. By providing new insights into the molecular mechanisms underlying EC progression, our research supports the development of novel therapeutic approaches that could contribute to improve treatment strategies for patients with EC.

[Assessment of tolerance of a new product (gluten-free grain snack) in children with food allergy to gluten].

The development of a technological scheme for the production of cereal snacks based on the extrusion process with preliminary enzymatic treatment of wheat flour and the use of hydrolysate as a partial replacement for gluten-free raw materials is an urgent task. The use of gluten-free cereal snacks in the diet opens up new possibilities for dietary therapy in patients suffering from various manifestations of food allergy to gluten, making their diet more diverse and meeting their individual needs. The purpose of the research was to clinically evaluate the tolerance of gluten-free cereal snacks in children with PA to gluten. Material and methods. The study included 21 patients (male and female) aged 3 to 17 years with a diagnosed food allergy, including gluten. All children received gluten-free cereal snacks according to their age: children from 3 to 7 years old (n=11) received 50 g (176 kcal) daily, and children aged 8 to 17 years old (n=10) received 100 g (352 kcal) daily for 14 days, in addition to a non-specific hypoallergenic diet excluding highly allergenic foods. On the first day of the study, the patients or one of their parents evaluated the organoleptic properties of the presented product (taste, color, smell) using a 5-point scale (1 - very bad, 5 - excellent), according to a specially designed questionnaire. The assessment of clinical symptoms over time related to skin, gastrointestinal tract, and nervous system was conducted using a second questionnaire, where parents kept a daily «observation log¼ reflecting the child's well-being and condition, as well as adverse events associated with taking the product. Clinical safety parameters were assessed based on the dynamics of complete blood count and blood immunological parameters (total IgE, specific IgE, and IgG4 antibodies to the studied allergens) at the beginning and end of the consumption period. Results. Daily examinations and patient questionnaires revealed no adverse reactions to the product. No significant differences in body weight were observed at the end of the study (p>0.05). In the results of clinical and immunological blood analysis before and after consuming gluten-free cereal snacks, no significant deviations were observed in the form of an increase in eosinophil count, total IgE, allergen-specific IgE and IgG4 antibodies in peripheral blood. This suggests a favorable clinical safety profile of the proposed product. Conclusion. The study found that consumption of the new product (gluten-free cereal snacks) was well-tolerated by children aged 3 to 17 years with various manifestations of food allergy: no adverse effects of the product or exacerbations of the underlying disease were observed during the 14-day period of gluten-free cereal snack consumption. Therefore, the studied gluten-free cereal snacks can be recommended for children aged 3 to 17 years with various manifestations of gluten FA, in combination with a gluten free diet.

Feasibility of biogas upgrading at a WWTP after pre-treatment application: Techno-economic assessment validation with pilot test data.

Improving the efficiency of anaerobic digestion (AD) of sewage sludge (SS) is a critical step toward the achievement of energy neutrality in wastewater treatment plants (WWTPs), as required by the European Green Deal. This study used a comparative techno-economic assessment (TEA) to evaluate the feasibility of producing biomethane, at a WWTP, through upgrading biogas with a double-stage permeation membrane plant. The biogas was originally generated from the AD of a mixture of primary sludge (PS) and either raw or pre-treated waste activated sludge (WAS), where biological or thermo-alkali pre-treatments were applied to increase the WAS intrinsic low degradability. The TEA was supported by the results of pilot-scale tests, carried out on WAS, which mimicked (i) a traditional mesophilic AD process; (ii) a two-stage AD process, where a temperature-phased anaerobic digestion (TPAD, 3 days, 55 °C + 20 days, 38 °C) was performed to biologically pre-treat WAS; (iii) a traditional mesophilic AD process preceded by a thermo-alkali (4 g NaOH/100 g TS, 90 °C, 90 min) pre-treatment. The TEA was carried out in two phases. In the first, the minimum size of the WWTP capable of making the costs necessary for the implementation of the biogas upgrading plant equal to the revenues coming from selling biomethane (at 62 €/MWh) in 10 years was calculated in the absence of pre-treatments. It resulted of 500,000 equivalent inhabitants (e.i.). In the second phase, for the WWTP size found previously, the effect of either biological or thermo-alkali pre-treatments on the economic balance was evaluated, that is the gain (or the loss) associated to the selling of biomethane, compared to the reference price of 62 €/MWh. It was found that the TPAD increased the biogas productivity by only 23.6%, too little to compensate the amount of heat necessary for the pre-treatment and the purchase cost of the additional reactor. Conversely, the thermo-alkali pre-treatment, which enhanced the WAS biogas productivity by 110%, increased the biomethane revenues by approx. 10 €/MWh, compared to the scenario without pre-treatments. This study offers useful data to WWTP managers who want to introduce WAS pre-treatments, combined with interventions for biogas upgrading, in a new or existing sludge line of a WWTP.

Potential Application of Egg White Peptides for Antioxidant Properties: Perspectives from Batch Stability and Network Pharmacology.

This study investigated the batch stability of egg white peptides (EWPs) during the enzymatic hydrolysis process, and confirmed the potential application of four crucial four peptides inoxidative damage repair. The results revealed that different batches of EWPs had good stability relating to antioxidant activity. With a similar sequence to confirmed antioxidant peptides, four EWPs (QMDDFE, WDDDPTD, DEPDPL, and FKDEDTQ) were identified withhigh repetition rates, and their potential to repair oxidative damage was investigated. Network pharmacology results showed that these four peptides could regulate the targets related to oxidative damage. Enrichment results demonstrated that these four peptides could influence the targets and pathways related to glutathione transferase activity (enrichment score: 148.0) and glutathione metabolism (p value: 9.22 × 10-10). This study could provide evidence for the batch stability of hydrolyzed prepared EWPs, and offer theoretical support for the development of antioxidant damage ingredients derived from foods.

Effect of aeration pretreatment on anaerobic digestion of swine manure.

To investigate the effects of aeration pretreatment on the anaerobic digestion (AD) of swine manure, five pretreatment groups were established with dissolved oxygen (DO) in each group set to 0.0, 0.4, 0.8, 1.4, and 2.0 mg/L, respectively. The results demonstrated that compared to the non-aeration group, methane production increased to varying degrees with different aeration pretreatments (AP), with a maximum increase of 27.98% (DO = 2.0 mg/L). AP reduced the hydrogen sulfide (H2S) content of biogas. The H2S concentration in the DO = 2.0 mg/L was only 0.209%, and this represented an increased H2S removal rate of 49.27% compared to that of the DO = 0.0 mg/L (0.412%). Simultaneously, AP increases the hydrolysis rate. When the DO concentration reached 2.0 mg/L, the hydrolysis rate reached its maximum. An increase in the hydrolysis rate further enhanced the removal rate of organic matter. The organic matter removal rate was highest (36.96%) at DO = 2.0 mg/L. AP effectively prolonged the methane generation time and shortened the lag time of methane generation. AP creates a brief micro aerobic environment, accelerates substrate hydrolysis, and promotes the production and consumption of total volatile fatty acids, particularly acetic acid. Additionally, AP promoted the symbiotic relationship between Caldicoprobacter (20.93%-34.96%) and Metanosaeta (14.73%-18.45%).

Hydrogen Peroxide-Assisted Alkaline Defluorination of the Fumigant and Potent Greenhouse Gas, Sulfuryl Fluoride: Hydrogen Peroxide as a Nucleophilic Reagent.

Sulfuryl fluoride (SO2F2, SF) is an effective and increasingly popular fumigant for treating buildings and commodities in international trade but has come under scrutiny as a potent greenhouse gas. Passage of vent gases through an alkaline spray has been proposed for scrubbing SF, but base hydrolysis is insufficiently fast and generates equal yields of fluoride and fluorosulfate, the latter of unknown environmental hazard. We report here that alkaline hydrogen peroxide (H2O2) markedly accelerates SF removal and gives nearly quantitative yield of fluoride, with fluorosulfate produced in less than 3.5% yield. The other major products are sulfate, peroxymonosulfate, and oxygen. The oxidation state of S was unchanged. Hydroxyl and superoxide radical scavengers had no effect on the rate. The reaction proceeds by sequential nucleophilic displacement of fluoride by hydroperoxide ion (HO2-) to form a transient diperoxysulfate species that rapidly undergoes intramolecular redox rearrangement to give sulfate and singlet oxygen. Peroxymonosulfate, produced through side reactions, can fully defluorinate SF as well, although more slowly. Two new peaks were detected in the 19F-NMR spectrum corresponding to intermediates. Fluoride can be removed conventionally, and the other products are innocuous or short-lived. Thus, H2O2-assisted alkaline defluorination promises to be an effective method for scrubbing spent SF fumes and preventing SF from reaching the atmosphere. This study highlights the benefits of H2O2 and peroxymonosulfate as nucleophiles in remediation chemistry.

Novel Roles of Catalysts in Producing High-purity High-pressure Hydrogen from Sodium Borohydride.

Hydrogen has received enormous attention as a clean fuel with its high specific energy (142 MJ/kg). To apply hydrogen as a practically available energy vector, the direct production of high-pressure hydrogen with high purity is pivotal, as it allows for circumventing the mechanical compression process. Recently, the concept of utilizing sodium borohydride (SBH) dehydrogenation as a chemical compressor that can generate high-pressure hydrogen gas was demonstrated by adopting formic acid as an acid catalyst. However, the presence of impurities (e.g., CO, CO2) in the final gas product requires an alternative method to enhance the use of SBH as a chemical compressor. Here, we highlighted the feasibility of producing high-purity, high-pressure hydrogen gas from the SBH dehydrogenation with and without Co-based catalysts. The scrutiny behind the thermodynamics and kinetics of the SBH dehydrogenation was conducted under the elevated pressure condition. As a result, the dual roles of the catalysts as proton collectors and heat sources were revealed, both of which are essential for improving hydrogen production efficiency. We hope that our research stimulates subsequent research that pave the way to exploit hydrogen as an energy vector and achieve a more sustainable future society.