Enzymatic Process Research Articles

Cost-Benefit Analysis of Enzymatic Hydrolysis Alternatives for Food Waste Management

In this study, we aimed to evaluate the economic, environmental, and social viability of the enzymatic hydrolysis process for food waste valorization by applying cost-benefit analysi (CBA). Our research was based on the investigation of three scenarios/alternatives for the final product of the enzymatic hydrolysis process and the production of bioethanol, bioactive peptides, and organic acids. Key economic indicators, such as cost/benefit ratios, net present value (NPV), and internal rate of return (IRR), were used to evaluate financial performance. At the end of the CBA, a sensitivity analysis was conducted to highlight the performance of each scenario under varying conditions, including fluctuating costs, benefits, and discount rates. These results indicate that enzymatic hydrolysis offers a significant opportunity for reducing food waste and its environmental impacts and promotes sustainability. Bioactive peptide production was found to be the most environmentally viable option, offering the highest cost-benefit efficiency. In both the optimistic and pessimistic scenarios of the sensitivity analysis, the results revealed that bioactive peptide production is economically viable, while the other alternatives, such as bioethanol and organic acid production, are more sensitive to economic and operational changes. This study revealed that enzymatic hydrolysis, as evaluated through CBA, offers a viable and impactful method for food waste management. It reduces environmental impacts, enhances sustainability, and aligns with the principles of a circular economy. The adoption of such innovative waste management strategies is considered essential for building a more sustainable and resource-efficient food system.

Screening, identification, and application of anaerobic ammonia oxidizing bacteria in activated sludge systems: A comprehensive review.

Anaerobic ammonium oxidation (Anammox) has garnered significant attention due to its ability to eliminate the need for aeration and supplementary carbon sources in biological nitrogen removal process, relying on the capacity of anaerobic ammonium oxidizing bacteria (AnAOB) to directly convert ammonium and nitrite nitrogen into nitrogen gas. This review consolidates the latest advancements in AnAOB research, outlining the mechanisms and enzymatic processes of Anammox, and summarizing the molecular biological techniques used for studying AnAOB, such as 16s rRNA sequencing, qPCR, and metagenomic sequencing. Additionally, it also overviews the currently identified AnAOB species and their distinct metabolic traits, while consolidating strategies to improve their performance. It further delineates coupled processes that utilize Anammox technology, offering practical insights for process selection. Eventually, the review concludes by suggesting future research directions and highlighting critical areas for further investigation. This review serves as a theoretical reference for the enrichment and cultivation of AnAOB, environmental impact management, and the selection of effective treatment processes.

Photoacids and Photobases: Applications in Functional Dynamic Systems.

Brønsted photoacids and photobases are a unique class of molecules that undergo a major change in their pKa values between their ground and excited states, resulting in donating or accepting a proton, respectively, but only after light excitation. This property of photoacids/photobases makes them an attractive tool for light-gating various dynamic processes. Here, we review the use of this property to manipulate functional dynamic systems with light. We discuss how a proton transfer event that can happen upon light excitation from a photoacid to a chemical moiety of a certain system or, vice versa, from the system to a photobase, can result in a shift in the equilibrium of the system, resulting in some dynamicity. We detail various systems, including self-assembly processes of nanostructures, self-propulsion of droplets, catalysis for hydrogen evolution or CO2 capturing, nanotechnological devices based on enzymatic processes, and changes in proton-conducting ionophores and materials. We detail the basic guidelines for using Brønsted photoacids and photobases in a desired system and conclude with the current technological gaps in further using these molecules.

Structural glycobiology - from enzymes to organelles.

Biological carbohydrate polymers represent some of the most complex molecules in life, enabling their participation in a huge range of physiological functions. The complexity of biological carbohydrates arises from an extensive enzymatic repertoire involved in their construction, deconstruction and modification. Over the past decades, structural studies of carbohydrate processing enzymes have driven major insights into their mechanisms, supporting associated applications across medicine and biotechnology. Despite these successes, our understanding of how multienzyme networks function to create complex polysaccharides is still limited. Emerging techniques such as super-resolution microscopy and cryo-electron tomography are now enabling the investigation of native biological systems at near molecular resolutions. Here, we review insights from classical in vitro studies of carbohydrate processing, alongside recent in situ studies of glycosylation-related processes. While considerable technical challenges remain, the integration of molecular mechanisms with true biological context promises to transform our understanding of carbohydrate regulation, shining light upon the processes driving functional complexity in these essential biomolecules.

Development of an enzymatic method for efficient production of DHA-enriched phospholipids through immobilized phospholipase A1 in AOT-water reverse micelles.

The demand for omega-3 polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), has been steadily increasing due to their significant health benefits. Traditional methods for producing DHA-enriched phospholipids often suffer from low efficiency and high costs. In this study, we developed an efficient enzymatic process to prepare phospholipid-DHA, which used immobilized phospholipase A1 to catalyze transesterification in AOT-water reverse micelle systems. Initially, high concentrations of free fatty acids were produced via acid hydrolysis of algae oil followed by crystallization. Among six evaluated reverse micelle systems, one was selected for further optimization. The substrate/enzyme ratio, temperature, reaction time, and water content were optimized using single-factor experiments and response surface methodology. To enhance cost-efficiency and eco-friendly practices, substrate recycling was implemented to maximize substrate utilization. This study established a comprehensive process chain for the preparation of phospholipid-DHA, promoting its industrial production and providing a reference for the production of other phospholipid products.

Optimizing the Enzymatic Hydrolysis of Bioflocculated Microalgae for Bioethanol Production

Spirulina platensis is a promising microalga, but biomass harvesting remains a challenge. Fungal bioflocculation offers a potential solution, facilitating the production of valuable bioproducts like bioethanol. Effective cell disruption methods, including physical-chemical and enzymatic treatments, can enhance biomass utilization. However, commercial enzymes are not optimized for microalgae, necessitating research on ideal operational conditions. This study evaluated physical and enzymatic processes to hydrolyze bioflocculated microalgae for bioethanol production. The microalga was harvested using a fungal bioflocculant produced via submerged fermentation. Biomass hydrolysis involved physical methods (autoclaving, ultrasound + autoclaving, ultrasound + gelatinization, and gelatinization) combined with enzymes (amylase, amyloglucosidase, cellulase, and xylanase), optimized for pH, temperature, and enzyme load. Hydrolysates were then used for bioethanol production. Results showed a microalgae harvest efficiency of 99.7% with a 1:8 fungus-to-microalgae ratio. Enzyme optimization identified ideal conditions (e.g., pH 4.5; 60 °C for amylase/amyloglucosidase, 70 °C for cellulase, and 50 °C for xylanase). Combined enzymatic treatments achieved approximately 70% hydrolysis efficiency, yielding 19.06 g/L glucose and 7.29 g/L ethanol (~79% conversion). Ethanol productivity was ~0.6 g per 1 g bioflocculated biomass L−1·hr. These findings highlight the potential of enzymatic hydrolysis for complex biomasses, although further studies are needed to refine enzyme applications for better biomass utilization.

Identification of Fungal Metabolite Gliotoxin as a Potent Inhibitor Against Bacterial O-Acetylserine Sulfhydrylase CysK and CysM

Cysteine is an essential amino acid for sustaining life, including protein synthesis, and serves as a precursor for antioxidant glutathione. Pathogenic bacteria synthesize cysteine via a two-step enzymatic process using serine as the starting material. The first step is catalyzed by serine acetyltransferase, also known as CysE, and the second by O-acetylserine sulfhydrylase (OASS), referred to as CysK or CysM. This cysteine biosynthetic pathway in bacteria differs significantly from that in mammals, making it an attractive target for the development of novel antibacterial agents. In this study, we aimed to identify OASS inhibitors. To achieve this, a high-throughput screening system was developed to analyze compounds capable of inhibiting CysK/CysM activity. Screening 168,640 compounds from a chemical library revealed that gliotoxin, a fungal metabolite, strongly inhibits both CysK and CysM. Furthermore, gliotoxin significantly suppressed the growth of Salmonella enterica serovar Typhimurium, a Gram-negative bacterium, under cystine-deficient conditions. Gliotoxin possesses a unique disulfide structure classified as epipolythiodioxopiperazine. To date, no studies have reported OASS inhibition by compounds with this structural motif, highlighting its potential for future structural optimization. The screening system developed in this study is expected to accelerate the discovery of functional CysK/CysM inhibitors, providing a foundation for novel antibacterial strategies.

Clinical evidence on nutrological management and gut microbiota in inflammatory bowel diseases: a systematic review

Introduction: The main risk factor for inflammatory bowel disease (IBD) is a positive family history. Crohn's disease (CD) can affect individuals aged 15 to 40 and 50 to 80 years, with a higher percentage in women. Ulcerative colitis (UC) can start at any age. Metabolism encompasses the interactions between diet, the microbiome, and cellular enzymatic processes that generate the chemical pathways necessary to sustain life. Endogenous metabolites and dietary nutrients can directly influence epigenetic enzymes. Epigenetic modifications to DNA and histone proteins alter cell fate by controlling chromatin accessibility and downstream gene expression patterns. Objective: It was to highlight the main interactions between nutrition and gut microbiota in the treatment of inflammatory bowel diseases. Methods: The present study followed the international systematic review model (PRISMA). This study was carried out from July to September 2024. It included randomized controlled, prospective, and retrospective studies published from 2013 to 2023. The Cohen test was performed to calculate the Effect Size and the inverse error standard (precision or sample size) for the risk of bias (Funnel Plot). Results and Conclusion: A total of 30 articles were found, and 17 clinical studies on the modulation of diet to control IBD were included in this study. These studies have shown reductions in persistent gut symptoms, improved gut microbiota, reduced markers of inflammation, and improved quality of life. Diet has an important role in controlling and even remitting IBD. The studies were homogeneous in results, with X2 = 82.5%, which increases the reliability of clinical results on the importance of diet in modulating IBD.

Pathway Elucidation and Key Enzymatic Processes in the Biodegradation of Difenoconazole by Pseudomonas putida A-3.

The extensive agricultural use of the fungicide difenoconazole (DIF) and its associated toxicity increasingly damage ecosystems and human health. Thus, an urgent need is to develop environmentally friendly technological approaches capable of effectively removing DIF residues. In this study, strain Pseudomonas putida A-3 was isolated for the first time which can degrade DIF efficiently. After optimization of the degradation conditions, the degradation rate reached 75.98%. Moreover, a new DIF degradation pathway, including hydroxylation, hydrolysis, dechlorination, and ether bond breaking. The acute and chronic toxicity of DIF degradation products assessed using ECOSAR software showed lower toxicity than the parent compound. Furthermore, strain A-3 remarkably accelerated the degradation of DIF in contaminated water-sediment systems. We successfully predicted six potential key enzymes for DIF degradation based on the results of whole genome sequencing, RT-qPCR, and molecular docking. Overall, the results revealed novel pathways for DIF biodegradation and provide a strong candidate for bioremediation of DIF residue-polluted environments.

Taming Highly Enolizable Aldehydes via Enzyme Catalysis for Enantiocomplementary Construction of β-Hydroxyphosphonates.

Taming highly enolizable aldehydes for catalytic asymmetric C-C coupling with nucleophiles remains an elusive challenge compared to widely explored simple alkyl or aryl aldehydes. Herein, we use ThDP-dependent enzymes to realize the direct C-C coupling of highly enolizable 2-phosphonate aldehydes with in situ-generated dynamically reversible nucleophiles (acyl anions). Unlike NHC-mediated reactions that yield complex mixtures of multiple adducts, our enzymatic process selectively produces biologically active β-hydroxy phosphonates with high yields (up to 95%) and excellent enantioselectivities (up to 99% ee). The products can be obtained on gram scales and exhibit rich reactivity for downstream transformations to afford diverse molecules. PfBAL (or its mutant A28G) and PaBAL enzymes serve as enantiocomplementary pairs, enabling the synthesis of both product configurations. Mechanistic studies proved that the entrance directions of the active cavities of these two enzyme pairs were distinct, leading to acyl anions formed from these two enzyme pairs attacking 2-phosphonate aldehydes from different orientations.

Mercury toxicity resulting from enzyme alterations- minireview.

Mercury is widely known for its detrimental effects on living organisms, whether in its elemental or bonded states. Recent comparative studies have shed light on the biochemical implications of mercury ingestion, both in low, persistent concentrations and in elevated acute dosages. Studies have presented models that elucidate how mercury disrupts healthy cells. Mercury's unique ability to interfere with crucial enzymatic processes at deposition sites is a vital feature of these models. The strong affinity for the sulfhydryl moieties of enzyme catalytic sites leads to enzyme inactivation through permanent covalent modifications. This inactivation can have catastrophic effects on an organism's metabolic functions. Moreover, it has been found that mercury's binding to sulfhydryl moieties is highly nonspecific and can occur in various ways. This review aimed to explore the effects of mercury on a broad spectrum of enzymes with a specific focus on how these alterations can detrimentally affect several metabolic pathways.

Micelle-enabled bromination of α-oxo ketene dithioacetals: mild and scalable approach via enzymatic catalysis.

The bromination of α-oxo ketene dithioacetals using KBr/H2O2, catalyzed by Curvularia inaequalis vanadium chloroperoxidase (CiVCPO), has been successfully demonstrated. A comparative study of enzymatic processes "on water" versus "in water", using 2 wt% of the surfactant TPGS-750-M revealed that the in-water protocol not only provides higher yields but also accommodates a broader substrate scope. This bromination method in an aqueous micellar medium enabled the preparation of brominated α-oxo ketene dithioacetals in fair to excellent yields (23 examples). In the micellar system, the substrate concentration was increased up to 50 mM, and the amounts of the brominating agents KBr and H2O2 were reduced to approximately 2.0 equivalents without compromising efficiency. Notably, this process allows for the gram-scale preparation of brominated α-oxo ketene dithioacetals in high yields. Key advantages of this method include its benign and eco-friendly nature, the use of water as a green solvent, and its potential for large-scale production of brominated α-oxo ketene dithioacetals.

Exo- and Endo-1,5-α-L-Arabinanases and Prebiotic Arabino-Oligosaccharides Production.

There is growing interest in pentose-based prebiotic oligosaccharides as alternatives to traditional hexose-based prebiotics. Among these, arabino-oligosaccharides (AOS), derived from the enzymatic hydrolysis of arabinan polymers, have gained significant attention. AOS can selectively stimulate the growth of beneficial gut bacteria, including Bifidobacterium and Bacteroides species, and contribute to health-benefit functions such as blood sugar control, positioning AOS as a promising synbiotic candidate. For the industrial production of AOS, the development of efficient enzymatic processes is essential, with exo- and endo-1,5-α-L-arabinanases (exo- and endo-ABNs) playing a crucial catalytic role. Most ABNs belong to the glycoside hydrolase (GH) family 43, characterized by a five-bladed β-propeller fold structure. These enzymes hydrolyze internal α-1,5-L-arabinofuranosidic linkages, producing AOS with varying degrees of polymerization. Some ABNs GH43 were known to exhibit exo-type hydrolytic modes of action, producing specific AOS products such as arabinotriose. Additionally, exo-ABNs from GH93, which feature a six-bladed β-propeller fold, exclusively release arabinobiose through their exo-type catalytic mechanism. This review represents the first comprehensive analysis of exo- and endo-ABNs, offering scientific insights into their biotechnological potential for AOS production. It systematically compares enzyme classification, structural differences, catalytic mechanisms, paving the way for innovative applications in health, food, and pharmaceutical industries.

Identification and Characterization of a New Thermophilic κ-Carrageenan Sulfatase.

Carrageenans are sulfated polysaccharides found in the cell wall of certain red seaweeds. They are widely used in the food industry for their gelling and stabilizing properties. In nature, carrageenans undergo enzymatic modification and degradation by marine organisms. Characterizing these enzymes is crucial for understanding carrageenan utilization and may eventually enable the development of targeted processes to modify carrageenans for industrial applications. In our study, we characterized a κ-carrageenan sulfatase, AMOR_S1_16A, belonging to the sulfatase S1_16 subfamily, which selectively desulfates the nonreducing end galactoses of κ-carrageenan oligomers in an exomode. Notably, AMOR_S1_16A represents the first κ-carrageenan sulfatase within the S1_16 subfamily and exhibits a novel enzymatic activity. This study provides further understanding of the substrate specificity and characteristics of the S1_16 subfamily. Moreover, this research highlights that many processes and enzymes remain to be discovered to fully understand carrageenan utilization pathways and to develop enzymatic processes for carrageenan modification and processing.

Coexpression of D-Allulose 3-Epimerase and L-Rhamnose Isomerase in Bacillus subtilis through a Dual Promoter Enables High-Level Biosynthesis of D-Allose from D-Fructose in One Pot.

D-Allose, a rare sugar, has gained significant attention not only as a low-calorie sweetener but also for its anticancer, antitumor, anti-inflammatory, antioxidant, and other pharmaceutical properties. Despite its potential, achieving high-level biosynthesis of D-allose remains challenging due to inefficient biocatalysts, low conversion rates, and the high cost of substrates. Here, we explored the food-grade coexpression of Blautia produca D-allulose 3-epimerase (Bp-DAE) and Bacillus subtilis L-rhamnose isomerase (BsL-RI) within a single cell using B. subtilis WB800N as the host. Using this system, D-allose was synthesized via a simple, cost-effective, one-pot enzymatic process, employing whole cells as catalysts and D-fructose as the substrate. The system exhibited optimal activity at 65 °C, pH 8.5, with 1 mM Mn2+ and 20 g/L of whole-cell dry weight. Initial production reached 12.5 g/L D-allose with a 12.5% yield from 100 g/L D-fructose. Optimization of dual promoter combinations enhanced production, achieving 15.0, 29.1, and 43.2 g/L D-allose from 100, 200, and 300 g/L D-fructose, with yields of 15.00, 14.55, and 14.40%, respectively. This D-allose production biocatalyst offers a scalable and economically viable platform for the industrial production of rare sugar.

Evaluating the Performance of Ethanol Electrochemical Nanobiosensor Through Machine for Predictive Analysis of Electric Current in Self‐Powered Biosensors

ABSTRACTIn this study, the focus is on ethanol nano biosensors based on alcohol oxidase (AOX) enzymatic reactions and the feasibility of generating electric current for biobatteries. The aim is to convert the latent energy in ethanol into electrical energy through the enzymatic oxidation process in the presence of an AOX enzyme. The release of electrons and the creation of a potential difference make the use of ethanol as a biofuel cell/self‐power biosensor in biologically sensitive systems feasible. To achieve this, glassy carbon electrodes were modified with gold nanoparticles to enhance conductivity, and the AOX enzyme was immobilized on the working electrode. The current generated through the enzymatic process was measured in various pH and analyte concentration conditions. Afterward, machine‐learning models, including multilayer perceptron (MLP), deep neural network, decision tree, and random forest, were employed to assess the impact of parameters on electric current generation, evaluate the error rate, and compare the results. The results indicated that the MLP model was the most suitable method for predicting the electric current produced under different pH, temperature, and ethanol concentration values. These findings can be utilized to identify optimal conditions and increase the current output for use as a reliable energy source in self‐powered biosensors. In conclusion, this study suggests a promising way to generate electricity by oxidizing ethanol with the AOX enzyme. The use of machine learning to analyze experimental data has provided insight into optimal conditions for maximizing electric current output for developing sustainable energy sources in biologically sensitive systems and biobattery technology.

Protein hydrolysates derived from superworm (Zophobas morio): Composition, bioactivity, and techno-functional properties.

This study aimed to produce protein hydrolysates from superworm (Zophobas morio) flour using the enzymes alcalase (HA), protamex (HP), or flavourzyme (HF), and to characterize their nutritional composition, techno-functional properties, bioactive capacity, and bioaccessibility index. The enzymatic process increased the total amino acid and crude protein contents of the hydrolysates by approximately 36% and 46%, respectively, generating better foaming capacity, oil retention, and emulsification capacity, when compared to raw flour. Although 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical capture was similar between the hydrolysates, HA (1479,66μM FeSO4/g) and HP (1514,66μM FeSO4/g) showed greater antimicrobial and iron reducing power (FRAP) activity, while HF has a higher scavenging efficiency for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (27.53%). The best antimicrobial activity was observed for HA against Vibrio corallilyticus (400mg/mL), and HP showed a better antioxidant response scavenging for DPPH radical. The antioxidant capacity against ABTS radical after in vitro simulation of gastrointestinal digestion (GID) was as follows: HA (79.07±1.53%), HP (74.65±5.85%), and HF (57.95±8.31%). Therefore, insect flour is a promising ingredient for the production of protein hydrolysates and their application in animal and human feeds.

ADAR1 Gene Polymorphism and Hematological Analysis in Responders and Relapse Patients with Chronic Myeloid Leukemia

Abstract Background: Chronic myeloid leukemia (CML) is defined by the Break point cluster region and Abelson Genes (BCR-ABL) fusion gene, which produces a continuously active tyrosine kinase known as the primary driver responsible for initiating and sustaining the disease. The RNA editing enzyme adenosine deaminase acting on double-stranded RNA 1 (ADAR1) converts adenosine into inosine in double-stranded RNA substrates. This enzymatic process is crucial in cellular RNA editing and can impact disease progression and therapeutic responses in CML. Objective: Analysis of ADAR1 gene polymorphisms, ADAR1 levels, and hematological parameters in Iraqi patients with CML. Materials and Methods: From January 2021 to February 2023, one hundred and twenty samples of whole blood were collected from patients with CML at the National Center of Hematology/Mustansiriyah University. The control group in this study comprised thirty samples of fresh whole blood. Total DNA genomic extraction was done to detect the ADAR1 gene polymorphism by sequencing. Furthermore, serum was used to detect ADAR1 enzyme level. Results: According to the age and male/female ratio, the patients’ groups were matching with control group. A group of CML patients on treatment, 65 out of 100 patients were on imatinib, while 35 were treated with other tyrosine kinase inhibitors. The patient groups in terms of age and gender ratio were matched with the control group. Among CML patients receiving treatment, 65 out of 100 were using imatinib, while 35 were treated with other tyrosine kinase inhibitors. In the newly diagnosed CML group, ADAR mutations were present in 35% of cases, and among treated CML patients, this proportion was 36%, whereas the control group showed no mutations (P < 0.001). The distribution of DNA polymorphisms—A/G, G/T, and G/G—was 42%, 30%, and 28%, respectively, among patients with CML, compared to 34%, 20%, and 46%, respectively, in the control group. There are significant differences between different groups according to genotyping of ADAR1 (P < 0.05). Based on ADAR1 mutation, there is a significant difference observed between the newly diagnosed CML group and the CML patients in the treatment group compared to the control group (P < 0.001). Specifically, the differences between the new diagnosis CML group and the treatment group were not statistically significant (P = 0.326). Furthermore, both the new diagnosis CML group and the relapse group showed significant differences compared to the control group (P < 0.001). The P value associated with the correlation between ADAR mutation and these groups is <0.001, indicating a highly significant correlation. Conclusion: The current findings suggest that ADAR1 polymorphisms and ADAR1 enzyme levels in Iraqi patients with CML could potentially influence disease progression and deepen our understanding of its mechanisms. These factors may also contribute to disease development and affect how patients respond to treatment.

A Mathematical Model of Ozone Distribution over Walnut Layer in a Vibrating Dryer

The most energy-intensive and time-consuming process in walnut processing technology is drying. As a rule, the moisture content is about 35-45 % during harvesting. Such conditions do not allow for storage and processing since high humidity creates favorable conditions to develop microbiological and enzymatic processes, which cause an intensive decrease in product quality. According to international standards, the moisture content should be decreased to 10 %. Including ozone in the composition of the drying agent allows for improving the energy performance of the drying process. One means for intensifying the drying process is the vibrational impact on the material layer. These two intensifying factors significantly improve the energy performance of the drying process. The article aims to increase the intensity and quality indicators of the drying process by developing a mathematical substantiation of the ozone distribution over the layer depth in a convective-vibration dryer using a comprehensive vibration-ozonating effect. The impact of the ozone-air mixture depends on distribution features and absorption by the entire layer in the drying chamber. The sorption and the ozone content in the coolant flow influence the ozone absorption parameters. A ratio characterizing the surface area blown with ozone can also be increased by transforming the walnut layer from stationary to quasi-boiling due to applying vibrational impact to the processed material. For the first time, the theoretical and experimental results made it possible to evaluate the performance of the ozone generator and the distribution law for ozone concentration depending on coolant velocity and vibration acceleration for the drying chamber. The obtained data showed that ozone concentration in the coolant at the inlet and outlet of the drying chamber is proportional to the vibration acceleration of the latter. The velocity of the drying agent of 8.5 m/s was achieved at the maximum magnitude of vibration acceleration for the concentration of 22.1–32.2 mg/m3. It was found that the average discrepancy in the ozone concentration range in the ozone-air mixture is achieved when leaving the dryer at 8–10 %, confirming the reliability of the developed mathematical model. It was also found that the average discrepancy in the range of ozone concentration in the ozone-air mixture when leaving the dryer is 8-10%, which confirms the adequacy of the developed mathematical model and the expediency of its further use. The article is devoted to solving the urgent problem of intensifying the convective process of drying walnuts with a comprehensive vibration-ozonating effect and a mathematical description of the ongoing process.

Hydrogenases – Types, Sources, Properties, and the Potential for Their Application

Hydrogenases are a group of versatile metalloenzymes that catalyse the reversible transformation between hydrogen gas and its constituent protons and electrons. These enzymes have gained attention more recently due to their ability to use molecular hydrogen as a substrate in the reactions they catalyse, as well as their potential to synthesise hydrogen, an important biofuel. Although the existence of hydrogenases has been known since the 1930s, current research has not yet made them viable on the industrial scale. They are explored mostly from the biochemical point of view, which is very important, but there is a lack of research on how to adapt these enzymes for real industrial-scale processes. Only a few studies address this gap. Therefore, in this brief literature review, we provide an overview of what is known about hydrogenases. We explore their background, classification, and phylogeny, highlighting their presence in many different sources in nature, such as bacteria, archaea, and certain eukaryotes. We also discuss key factors influencing their activity, along with their advantages and disadvantages. Furthermore, we summarise the methods available for determining their activity and emphasise the need for standardised units to ensure comparability of all data available in the literature. Finally, we discuss their potential applications, particularly in hydrogen production and synthetic reaction pathways for coenzyme regeneration, emphasizing the critical importance of these aspects in the investigation of hydrogenases.