Search Results (221)

Anaerobic digestion (AD) plays a key role in the circular bioeconomy by converting organic waste into renewable energy and facilitating the sustainable utilisation of waste materials. Agricultural and agro-industrial by-products are increasingly recognised as valuable AD feedstocks due to their widespread availability and significant bioenergy potential. However, many of these substrates contain plant-derived bioactive compounds, such as polyphenols, tannins, flavonoids and terpenes, which can influence microbial communities and process performance. Depending on their concentration and chemical characteristics, these compounds may inhibit microbial activity, impair process stability, and ultimately decrease methane production. This review critically synthesises current knowledge on the occurrence, bioavailability and biological activity of plant-derived bioactive compounds in agricultural feedstocks used for anaerobic digestion, with particular emphasis on their implications for process performance and reactor stability. The principal mechanisms through which phytochemicals influence anaerobic digestion include enzyme inhibition, membrane disruption, interference with syntrophic interactions and trace metal chelation. The available evidence demonstrates a pronounced dose-dependent response, whereby low concentrations may exert neutral or selective modulatory effects. In contrast, elevated concentrations disrupt microbial activity, leading to volatile fatty acid accumulation, prolonged lag phases and reduced methane production. Current mitigation strategies include substrate pretreatment, co-digestion, microbial adaptation, adsorbent-assisted detoxification and the use of DIET-promoting materials. An integrated evidence matrix is proposed to link phytochemical composition with reactor configuration, operational parameters and mitigation strategies, thereby providing a practical framework for feedstock-specific process optimisation. Overall, the available evidence demonstrates that reliable evaluation of agricultural feedstocks should extend beyond conventional biochemical methane potential assessment to incorporate phytochemical composition, microbial functional responses and key operational parameters. Such an integrated approach can improve the prediction of methane recovery and support evidence-based optimisation of anaerobic digestion within circular bioeconomy systems. Full article

Lentinus edodes stipe is an under-utilised processing by-product that holds potential as a natural umami source. This study systematically compared nine enzymatic hydrolysis combinations, including single proteases, cellulase, and double enzyme systems comprising both protease–protease and protease–cellulase mixtures, to optimise the release of taste-active and volatile flavor compounds from the stipes. The Flavourzyme-only hydrolysate achieved the highest degree of hydrolysis (50.38%), the richest 5′-nucleotides (5.46 mg/g), free amino acids (59.06 mg/g) and volatile compounds (150.23 μg/kg), and an equivalent umami concentration of 288 g monosodium glutamate equivalent per 100 g matter. It also delivered the strongest umami taste and the lowest bitterness in sensory evaluation. The double-enzyme systems consistently underperformed due to competitive substrate binding, suboptimal pH for companion enzymes, and potential mutual protease digestion. Among the volatile compounds, 1,2,4-trithiolane and cedrol were identified as key aroma differentiators by multivariate analysis. These findings demonstrate that Flavourzyme alone constitutes the optimal enzymatic system for producing clean-tasting, umami-rich condiments from L. edodes stipes and caution against indiscriminate enzyme blending without prior compatibility assessment. The optimized hydrolysis process provides a scalable route for the industrial valorisation of mushroom processing by-products. Full article

The common products of acidogenesis, the key stage in the process of anaerobic digestion, are lactate, butyrate, propionate, and acetate. They were decomposed in the Up-flow Anaerobic Sludge Blanket bioreactors working in continuous-flow open systems. A comprehensive analysis of variations in both isotopic ratios and concentrations of organic acids in the effluents was conducted to enhance comprehension of methanogenic processes. The analysis of carbon isotope fractionation in the CO₂-CH₄ system, as evidenced by the α¹³C_CO2-CH4 factor, has indicated that acetate decarboxylation has occurred. Furthermore, a decline in CO₂ levels was observed, accompanied by the predominance of butyrate and propionate, despite the presence of acetic acid in the effluents from all the bioreactors. Butyric acid demonstrated the greatest resistance to decomposition, resulting in ¹³C-enrichment of DIC. Lactic acid was utilised almost entirely. The observations presented above were subsequently validated through statistical analysis. A comparative analysis of the δ¹³C(CH₄) and δ¹³C(CO₂) values of our study with those of other natural substrates (detritic lignite, xylite, maize silage, and cattle manure) was undertaken, and it was found that isotope fractionation differs significantly in closed (potential thermodynamic processes) and open systems (expected Rayleigh processes). In the context of open systems, the isotope fractionation factor α¹³C_CO2-CH4 during methaneogenesis has been observed to attain values that are consistent with those observed in CH₄ oxidation. The study revealed that the presence of acetate in the substrate (i.e., the M4 bioreactor) led to the generation of CO₂ with a higher proportion of light carbon isotopes. This, in turn, resulted in a shift in the isotope fractionation factor (i.e., α¹³C_CO2-CH4) to values below 1.03. Our results suggest that methanogenic pathway signatures in open, continuous-flow systems may only be partially apparent. This is because substrate depletion drives Rayleigh-type isotope enrichment, while the dominance of a single substrate and its constant inflow stabilise pathway expression and shift control towards substrate dynamics rather than intrinsic microbial changes. Our finding suggests that isotope-based diagnostics could enhance process control in biogas plants by identifying substrate-driven limitations and facilitating more efficient and stable CH₄ production. Full article

This study investigated lactic fermentation of green buckwheat beverages formulated at 8% (A, AA) and 10% (B, BB) solids using single- and multiple-strain cultures of Lactiplantibacillus plantarum, Lactobacillus acidophilus, Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus. Fermentation at 37 °C rapidly reduced pH from slightly alkaline values (7.44–7.57) to approximately 4.2–4.5 within 3–8 h, while viable counts increased from near-zero to 8–9 log₁₀CFU mL⁻¹, confirming efficient lactic acid bacteria (LAB) proliferation in all substrates. A general trend was observed in the sugar consumption strategy of studied LAB: sucrose (after hydrolysis) and glucose were almost completely depleted within 6–8 h, fructose was consumed more slowly, and raffinose remained largely unchanged, with the 10% substrate mainly accelerating early sugar turnover without altering final cell densities or the qualitative utilisation pattern. Dry matter changed little during fermentation, whereas total phenolic content (TPC) and total tannin content (TTC) were strongly affected in a matrix- and strain-dependent manner. At 8% solids, fermentation promoted substantial TTC reduction and, for several cultures, a net decrease in extractable phenolics. In contrast, 10% formulations, particularly those inoculated with L. acidophilus and L. paracasei (alone or in combination), partially preserved or increased TPC while achieving more moderate tannin losses. Overall, green buckwheat proved to be a promising substrate for developing fermented beverages in which solids level and starter composition can be tuned to combine rapid acidification and high LAB viability with tailored sugar depletion and favourable modulation of phenolic and tannin fractions. Full article

The growing reliance on cyber deception as a defensive mechanism has revealed persistent limitations in existing deception infrastructures, particularly in their ability to scale, adapt, and provide continuous observability under realistic adversarial workloads. Conventional honeypot deployments are predominantly monolithic and statically configured, which constrains their responsiveness to dynamic attack conditions and limits their applicability in contemporary distributed environments. This work presents a microservice-oriented cyber deception platform that reconceptualizes deception infrastructure as a composition of loosely coupled, independently deployable services. The platform integrates containerized honeypots, a lightweight API-driven orchestration layer, and a centralized telemetry pipeline to enable rapid instantiation, dynamic reconfiguration, and high-resolution monitoring of attacker interactions. Unlike prior approaches that treat deployment, orchestration, and monitoring as separate concerns, the proposed design explicitly unifies these components within a single, measurable system architecture. To support principled reasoning about system behaviour, the paper introduces first-order analytical models that characterize deployment latency, resource utilisation, telemetry throughput, and operational cost as functions of attacker concurrency. These models are not intended as exact predictors, but as tractable abstractions that enable interpretation of system performance and guide capacity planning. Model parameters are empirically derived and validated through controlled experimentation. Evaluation is conducted within a reproducible cyber-range environment using scripted adversarial workloads that emulate reconnaissance, authentication attempts, and sustained interactive sessions. The results indicate that containerised deployment reduces instantiation latency to approximately 1.2 s under warm-start conditions, compared to tens of seconds for virtual machine-based baselines. Resource utilisation exhibits approximately linear scaling under moderate concurrency, while the telemetry pipeline sustains ingestion rates exceeding 18,000 events per minute without observable loss. Stress testing further reveals that telemetry processing, rather than orchestration, constitutes the primary scalability bottleneck. These findings suggest that microservice-based architectures can provide a viable and extensible infrastructure substrate for cyber deception, supporting both operational deployment and integration with higher-level adaptive and learning-based defence mechanisms. The contribution of this work lies not in introducing new deception strategies, but in enabling their practical realisation through a scalable and observable system design. Full article

Postoperative atrial fibrillation (POAF) is the most frequent post-cardiac surgical arrhythmia and is associated with haemodynamic instability, longer hospital stays, higher healthcare utilisation, stroke and adverse long-term outcomes. Conventional models of POAF focus on advancing age, pre-existing atrial substrate, increasing operative complexity, inflammatory responses related to cardiopulmonary bypass, disturbances in autonomic balance, and acute metabolic insults during the perioperative period. Although these explanations are important, they may be incomplete. Malignancy and the cancer-associated systemic environment involve biological processes potentially relevant to postoperative atrial vulnerability, such as chronic inflammation, oxidative stress, impaired vascular function, hypercoagulability, altered immune response, frailty, and treatment-related myocardial, pericardial, or conduction-system injury. This review assesses whether malignancy should be regarded as an underrecognised modifier of susceptibility rather than as a coincidental comorbidity. Most available data are extrapolated from cardio-oncology and thoracic oncology studies or general studies related to atrial fibrillation (AF) rather than studies focused on cardiac surgery. While malignancy cannot be dismissed as irrelevant to the generation of POAF, it also does not permit causal inference. Future studies should move beyond binary cancer status and incorporate cancer activity, treatment exposures, biomarker profiles, and atrial substrate measures to determine whether malignancy improves perioperative POAF risk stratification. Full article

Twelve white-rot fungal isolates were evaluated for their potential to produce mycelium leather from rice straw, based on growth characteristics, biomass production, and mechanical properties. Among these, Trametes sp. SW25-2 exhibited rapid growth on culture medium and dense mycelial formation on rice straw substrate. The effects of nutrient supplementation, substrate-to-medium ratio, and processing conditions on mycelium-leather formation were systematically examined. No significant differences were observed among different carbon (glucose, maltose, and sucrose) and nitrogen sources (yeast extract, peptone, and ammonium sulphate), indicating that the fungus effectively utilised rice straw as the primary substrate. An optimal ratio of 1 g rice straw to 10 mL culture medium (90.9% moisture content) enabled complete colonisation and the formation of a compact mycelial structure, achieving a maximum tensile strength of 2.78 MPa under optimised hot-pressing conditions (120 °C, 60 s, 1 MPa). Hot-pressing conditions significantly influenced material properties. A higher temperature (120 °C) increased tensile strength but reduced elongation at break, while a lower temperature (60 °C) produced more flexible materials. Scanning electron microscopy revealed that post-treatment and hot pressing transformed the mycelial network into a dense and cohesive structure. The resulting mycelium leather demonstrated suitable physical properties and was successfully fabricated into prototype products, highlighting its potential as a sustainable bio-based material derived from agricultural waste. Full article

Solid amine adsorbents can capture CO₂ at indoor-relevant concentrations (~1000 ppm), but many high-capacity adsorbents rely on granular or powdery supports that are difficult to integrate directly into air purification systems. Here, we applied three amination strategies to commercial fibrous substrates: bridge-grafting on viscose (TEPA-AMVF), direct grafting on polyacrylonitrile (TEPA-PAN), and physical impregnation on pore-engineered activated carbon fibre felt (PEI-ACF). These adsorbents were systematically screened under simulated indoor conditions (1000 ppm CO₂, 27 °C, 50% RH). A significant capacity difference was observed: TEPA-AMVF (24.8 mg g⁻¹) < TEPA-PAN (35.8 mg g⁻¹) ≪ PEI-ACF (97.0 mg g⁻¹). The superior performance of PEI-ACF was attributed to KOH activation, which produced a mesopore-rich structure (average pore diameter 26.1 nm at an optimal KOH/carbon ratio of 1.25) and enabled high nominal amine utilisation (0.19 mmol CO₂ mmol N⁻¹). PEI-ACF maintained high breakthrough-derived CO₂ uptake across realistic indoor conditions (64.2–118.6 mg g⁻¹ over 0%–100% RH; 71.6–124.5 mg g⁻¹ over 400–5000 ppm CO₂), exhibited rapid kinetics (pseudo-first-order rate constant k = 1.77 h⁻¹; 81.7% of equilibrium uptake within 1 h), and showed stable but partial regeneration over four adsorption–desorption cycles at 60–70 °C under N₂. Compared with granular or resin-based amine sorbents, the self-supporting PEI-ACF felt is expected to offer practical advantages for filter-integrated CO₂ removal, including mechanical integrity under airflow, reduced risk of particle leakage, and compatibility with HVAC filter slots. Remaining challenges include direct pressure-drop validation, operation in O₂-containing indoor air, long-term cycling, and management of CO₂ released during regeneration. Full article

The agricultural sector generates substantial waste that harms both the environment and human health. This study aimed to utilise Metschnikowia yeasts to convert native agricultural wastes without chemical pretreatment. Ten Metschnikowia isolates were assessed using API tests to identify their assimilation profiles and enzymatic activities. Yeast growth was evaluated via the plate count method. The culture media containing molasses, brewery spent grain, and postharvest sunflower parts were characterised chromatographically, and the in vitro impact on Verticillium tenerum phytopathogen was evaluated. The effect of the yeast preparations on Caco-2, IEC-6, and HaCaT cell lines was also investigated. Solid waste materials without preliminary chemical pretreatment supported yeast multiplication to 4.5 × 10⁷–1.3 × 10⁸ CFU/mL. The metabolite composition and enzymatic activity of lipase, glucosidase, and protease in post-culture media suggest that they may act as growth inhibitors of the Verticillium strain. For post-cultivation samples, inhibition coefficients were equal to 1.24–2.00, depending on the kind of substrate and yeast strain used. Antimicrobial activity was also noted in cell-free samples after yeast cultivation on sunflower stalks and brewery spent grain. The toxicological analysis showed that the yeast preparations did not cause toxic effects on the tested cell lines. This research offers a sustainable approach using Metschnikowia yeasts, highlighting the importance of a holistic method that combines microbiological, biochemical, and toxicological aspects for sustainable waste management and the development of new applications, such as feed supplements and biocontrol agents. Full article

The large yellow croaker (Larimichthys crocea) is a high-value marine fish, but stress during live transport often leads to physiological disturbance and deterioration of muscle quality. This study investigated the effects of pre-transport temporary rearing at three temperatures (8, 10, and 12 °C) over 48 h on stress response, energy allocation, and muscle quality in this fish species. Temporary rearing at 8 °C induced stronger cold stress, characterised by elevated cortisol, marked lipid mobilisation, late lactate rebound, and greater loss of polyunsaturated fatty acids, indicating enhanced stress–catabolism coupling and higher risk of quality deterioration. In contrast, 12 °C did not sufficiently suppress metabolic turnover, resulting in continuous glycogen depletion, rapid ATP degradation, and accelerated accumulation of bitter-tasting nucleotide metabolites such as hypoxanthine. Among the tested temperatures, 10 °C showed the most coordinated response, with relatively stable endocrine status, moderate substrate utilisation, lower accumulation of undesirable degradation products, and better preservation of texture, water-holding capacity, and flavour-related precursors. These findings suggest that 10 °C is a promising pre-transport temporary rearing temperature for large yellow croakers under the present 48 h experimental conditions. The advantage of this temperature appears to lie in achieving a more favourable balance between metabolic suppression and physiological homeostasis, thereby providing a scientific basis for improving pre-transport rearing management and supporting safer, more stable live transport. Future studies incorporating behavioural and molecular indicators are needed to further clarify the regulatory effects of 10 °C during pre-transport rearing. Full article

Aluminium alloys are extensively considered in aviation and automobiles owing to their lightweight properties and favourable specific strength-to-weight ratio. Generally, the poor surface properties of these alloys limit their application, particularly in sliding conditions. To enhance the surface qualities, particularly the material’s wear resilient features, a unique surface modification process using electro-discharge coating (EDC) has been employed. This work investigates the optimisation of coating variables produced by the EDC technique utilising green compact electrodes composed of 50 wt.% tungsten disulfide (WS₂) and 50 wt.% copper (Cu) powder. The substrate material utilised was AA7075 alloy. The Taguchi–TOPSIS approach was employed to determine optimal EDC process variables, with pulse-on time (T_on), current (I_p), and pulse-off time (T_off). Wear rate (WR), surface roughness (SR), and friction coefficient (CoF) were used to assess the coating features. A wear study was performed with a pin-on-disc device with an undeviating sliding speed (0.25 m/s) and a 25 N load. The results revealed that the supreme features derived from the linear plots were I_p (4 A), T_on (80 µs), and T_off (5 µs). The ANOVA found that I_p had the utmost significant impact, accounting for 44.09%; T_off, 28.01%; T_on, 20.33%; and minimum error, 8.58%. A validation trial with perfect parameters returned values of 0.000179 mm³/Nm (WR), 0.204 (CoF), and 2.818 µm (SR). These findings are significantly better than those of the other coatings. The discrepancy among the estimated and experimental relative closeness in optimal settings is 6.34%, demonstrating that the Taguchi–TOPSIS method is more appropriate for multi-criteria optimisation. Full article

To broaden the application of biomethanation for energy storage and renewable integration, this study investigates the performance of a trickle-bed reactor (TBR) for hydrogen (H₂) utilisation in biogas upgrading, using both pure Carbon dioxide (CO₂) and biogas-derived CO₂ as substrates for methane (CH₄) production. Renewable sources such as wind and solar are inherently variable, increasing the need for scalable storage solutions. Converting surplus electricity into H₂ and CH₄ via biological methanation offers an efficient and safer alternative to direct H₂ storage. By reducing CO₂ produced by biogas plants, methanogenic archaea produce CH₄, enabling H₂ valorisation and enhanced biogas yields. This study demonstrates that TBR technology can achieve CH₄ formation rates up to 15 L-CH₄/L-reactor/day under optimised conditions. Siporax carrier material supported dense biofilm formation and effective gas–liquid mass transfer, facilitating high conversion efficiency. The system showed operational robustness, with rapid recovery after prolonged idle periods and stable production rates of 10–12 L-CH₄/L/day. Wastewater was used as a realistic medium to assess reactor performance under complex, variable conditions. Reactor design focused primarily on enhancing gas–liquid mass transfer and supporting sustained microbial activity through adequate nutrient supply, ensuring sufficient buffer capacity to maintain pH stability. These results demonstrate the potential of TBR-based systems for high-rate, stable biomethanation and highlight their applicability in future energy infrastructures for integrating H₂ through decentralised biogas upgrading. Full article

Underutilised, nutrient-dense legumes in their sprouted form provide promising substrates for developing functional fermented foods capable of influencing gut microbial activity and metabolite production. This study evaluated the effects of probiotic lactic acid bacteria-fermented beverages derived from sprouted Bambara groundnut (Vigna subterranea) and cowpea (Vigna unguiculata) on gut microbiota composition and short-chain fatty acid (SCFA) production using an in vitro colonic fermentation model. The beverages were fermented with either Bifidobacterium animalis BB-12 (BCBF24) or Lactiplantibacillus plantarum 75 (BCL7524). During colonic fermentation, at 0, 12, 24, and 38 h, faecal slurries were collected for SCFA analysis using gas chromatography–mass spectrometry (GC-MS) and deoxyribonucleic acid (DNA) sequencing (Oxford Nanopore Technologies). Microbial diversity decreased, indicating selective enrichment of taxa. BCL7524 induced a major shift, significantly (p < 0.05) enriching Bacillota and driving Megasphaera to ~42% dominance within 24 h. This reflected cross-feeding from L. plantarum to lactate-utilising Megasphaera spp. Spearman correlation linked Megasphaera to a broad SCFA profile, including isobutyric, isovaleric, valeric, and hexanoic acids, with a significant (p < 0.05) positive correlation observed for hexanoic acid. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated proteolysis and mapped hexanoic acid to fatty acid biosynthesis pathways, suggesting chain-elongation activity contributing to hexanoate formation. In line with this, BCL7524 produced significantly (p < 0.05) higher levels of hexanoate (3–14 mM) and valerate (10–15 mM), supporting chain-elongation activity within the community. In contrast, BCBF24 enriched Actinomycetota and Bifidobacterium, correlating with acetate production (18–23 mM). This study demonstrates that specific synbiotic beverages can modulate gut microbial ecology and metabolic output under in vitro conditions. Full article

This study presents a low-cost, small-scale single-chamber microbial fuel cell (MFC) toxicity biosensor fabricated on a printed circuit board (PCB) and a 3D-printed chamber with a volume of 120 μL. The anode consists of a screen-printed carbon electrode on the PCB, while the air cathode is a carbon paper electrode. To address poor adhesion of microorganisms to the smooth anode surface, femtosecond laser processing was used to fabricate a micropore array with 40 μm pores on the electrode. This method can create micropores on the anode surface without damaging the screen-printed electrodes, the PCB substrate, or the pads. These micropores increase the anode’s surface area and hydrophilicity, allowing more microbial coatings to firmly adhere to its surface. In this study, the MFC utilised Rhizobium rosettiformans W3, extracted from activated sludge at a wastewater treatment plant, as the anode microorganism. Its aerobic nature simplifies the design of MFCs, enabling a single-chamber structure and miniaturisation. Using formaldehyde solution as a toxicity sample to test the biosensor’s performance, a 0.1% concentration significantly reduced the sensor’s output power. Full article

Energy homeostasis arises from a complex interplay between gut-derived hormones, the central nervous system, and pancreatic function. Beyond the classical incretin axis, a broad spectrum of gut peptides acts in concert to coordinate appetite regulation, nutrient sensing, gastric motility, and systemic bioenergetic balance. Perturbation of this network contributes to metabolic disorders such as obesity, type 2 diabetes, and cachexia, underscoring its pivotal role in physiological and pathological energy regulation. This review provides an integrated analysis of the mechanisms through which gut–brain–pancreas communication maintains metabolic homeostasis, with particular attention to the dynamic cross-talk between peripheral endocrine signals and central regulatory circuits. Alterations in these pathways are examined in relation to their impact on energy expenditure and substrate utilisation, alongside recent translational efforts exploiting multi-receptor peptide agonism and combinatorial hormonal modulation to restore metabolic equilibrium. Emerging therapeutic approaches increasingly aim to engage multiple bioenergetic pathways simultaneously, supported by advances in peptide engineering and molecular design. By conceptualising metabolic regulation as a coordinated network rather than a linear hormonal cascade, this article delineates a physiological and translational framework for next-generation interventions targeting bioenergetic dysfunction in human disease. Full article