Search Results (392)

With the growth of the plant-based food sector, increasing amounts of by-products are generated. Sea buckthorn pomace (SBP), a by-product of juice and other manufacturing products, is rich in bioactive compounds such as phenolics, oligosaccharides, proteins, and dietary fiber. The aim of the study was to evaluate the impact of modification methods, such as enzymatic hydrolysis and supercritical carbon dioxide extraction (SFE-CO₂), on the chemical composition and technological properties of SBP. SBP and SBP obtained after SFE-CO₂ (SBP-CO₂) were enzymatically modified using Pectinex^® Ultra Tropical, Viscozyme^® L, and Celluclast^® 1.5 L (Novozyme A/S, Bagsværd, Denmark). The SBP’s main constituent was insoluble dietary fiber (IDF), followed by crude proteins and lipids (respectively, 58.7, 21.1 and 12.6 g/100 in d.m.). SFE-CO₂ reduced the lipid content (by 85.7%) in the pomace while increasing protein and TDF content. Enzymatic hydrolysis decreased the content of both soluble dietary fiber (SDF) and IDF, and increased the content of mono- and oligosaccharides as well as free phenolics, depending on the commercial enzyme preparation used in SBP and SBP-CO₂ samples. Celluclast^® 1.5 L was the most effective in hydrolyzing IDF, while Viscozyme^® L and Pectinex^® Ultra Tropical were the most effective in degrading SDF. Enzymatic treatment improved water swelling capacity, water retention capacity, water solubility index, oil retention capacity of SBP and SBP-CO₂; however, it did not have a significant effect on the stability of the emulsions. Modification of SBP by SFE-CO₂ effectively increased WSC and WSI, however it reduced WRC. These findings highlight the potential of targeted modifications to enhance the nutritional and technological properties of SBP for functional food applications. Full article

Background/Objectives: A nanostructured membrane of polycaprolactone (a synthetic polymer) was synthesized using an electrospinning technique aiming to enhance its hydrophilicity and rate of degradation by surface modification via aminolysis. Since polycaprolactone nanofibrous films are naturally hydrophobic and with slow degradation, which restricts their use in biological systems, amino groups were added to the fiber surface using the aminolysis technique, greatly increasing the wettability of the membranes. Methods: Polycaprolactone nanofibrous membranes were synthesized via the electrospinning technique and surface modification by aminolysis. Trypsin, pepsin, and pancreatin were conjugated onto the aminolyzed PNF surface to further strengthen biocompatibility by enhancing the hydrophilicity, porosity, and biodegradation rate. SEM, FTIR, EDX, and liquid displacement method were performed to investigate proteolytic efficiency and morphological and physical characteristics such as hydrophilicity, porosity, and degradation rates. Results: Enzyme activity tests, which showed a zone of clearance, validated the successful enzyme conjugation and stability over a wide range of pH and temperatures. Scanning electron microscopy (SEM) confirms the smooth morphology of nanofibers with diameters ranging from 150 to 950 nm. Fourier transform infrared spectroscopy (FTIR) revealed the presence of O–H, C–O, C=O, C–N, C–H, and O–H functional groups. Energy-dispersive X-ray (EDX) elemental analysis indicates the presence of carbon, oxygen, and nitrogen atoms owing to the presence of peptide and amide bonds. The liquid displacement technique and contact angle proved that Pepsin-PNFs possess notably increased porosity (88.50% ± 0.31%) and hydrophilicity (57.6° ± 2.3 (L), 57.9° ± 2.5 (R)), respectively. Pancreatin-PNFs demonstrated enhanced enzyme activity and degradation rate on day 28 (34.61%). Conclusions: These enzyme-conjugated PNFs thus show improvements in physicochemical properties, making them ideal candidates for various biomedical applications. Future studies must aim for optimization of enzyme conjugation and in vitro and in vivo performance to investigate the versatility of these scaffolds. Full article

Spent coffee grounds (SCG) are a widely available agro-industrial residue rich in carbon and phenolic compounds, presenting significant potential for biotechnological valorization. This study evaluated the use of SCG as a suitable substrate for fungal laccase production and the application of the resulting fermented biomass (RFB), a mixture of fermented SCG and fungal biomass as a biosorbent for textile dye removal. Two fungal strains, namely Lentinus crinitus UCP 1206 and Trametes sp. UCP 1244, were evaluated in both submerged (SmF) and solid-state fermentation (SSF) using SCG. L. crinitus showed superior performance in SSF, reaching 14.62 U/g of laccase activity. Factorial design revealed that a lower SCG amount (5 g) and higher moisture (80%) and temperature (30 °C ± 0.2) favored enzyme production. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses confirmed significant structural degradation of SCG after fermentation, especially in SSF. Furthermore, SCG and RFB were chemically activated and evaluated as biosorbents. The activated carbon from SCG (ACSCG) and RFB (ACRFB) exhibited high removal efficiencies for Remazol dyes, comparable to commercial activated carbon. These findings highlight the potential of SCG as a low-cost, sustainable resource for enzyme production and wastewater treatment, contributing to circular bioeconomy strategies. Full article

Fluorinated xenobiotics, such as per- and polyfluoroalkyl substances (PFAS), fluorinated pesticides, and pharmaceuticals, are extensively used across industries, but their extreme persistence, driven by the high carbon–fluorine (C–F) bond dissociation energy (~485 kJ/mol), poses serious environmental and health risks. These compounds have been detected in water, soil, and biota at concentrations from ng/L to µg/L, leading to widespread contamination and bioaccumulation. Traditional remediation approaches are often costly (e.g., EUR >100/m³ for advanced oxidation), energy-intensive, and rarely achieve complete degradation. In contrast, microbial defluorination offers a low-energy, sustainable alternative that functions under mild conditions. Microorganisms cleave C–F bonds through reductive, hydrolytic, and oxidative pathways, mediated by enzymatic and non-enzymatic mechanisms. Factors including electron donor availability and oxygen levels critically influence microbial defluorination efficiency. Microbial taxa, including bacteria, fungi, algae, and syntrophic consortia, exhibit varying defluorination capabilities. Metagenomic and microbial ecology studies continue to reveal novel defluorinating organisms and metabolic pathways. Key enzymes, such as fluoroacetate dehalogenases, cytochrome P450 monooxygenases, reductive dehalogenases, peroxidases, and laccases, have been characterised, with structural and mechanistic insights enhancing the understanding of their catalytic functions. Enzyme engineering and synthetic biology tools now enable the optimisation of these enzymes, and the design of microbial systems tailored for fluorinated compound degradation. Despite these advances, challenges remain in improving enzyme efficiency, broadening substrate specificity, and overcoming physiological constraints. This review emphasises the emerging promise of microbial defluorination as a transformative and green solution, uniquely integrating recent multidisciplinary findings to accelerate the development of sustainable microbial defluorination strategies for effective remediation of fluorinated xenobiotics. Full article

Microbial decomposition of persistent natural compounds such as phenolic lignin and polysaccharides in plant cell walls plays a crucial role in the global carbon cycle and underpins diverse biotechnological applications. Among microbial decomposers, fungi from the Ascomycota and Basidiomycota phyla have evolved specialized mechanisms for efficient lignocellulosic biomass degradation, employing extracellular enzymes and synergistic fungal consortia. Fungal coculture, defined as the controlled, axenic cultivation of multiple fungal species or strains in a single culture medium, is a promising strategy for industrial processes. This approach to biomass conversion offers potential for enhancing production of enzymes, biofuels, and other high-value bioproducts, while enabling investigation of ecological dynamics and metabolic pathways relevant to biorefinery operations. Lignocellulosic biomass conversion into fuels, energy, and biochemicals is central to the bioeconomy, integrating advanced biotechnology with sustainable resource use. Recent advancements in -omics technologies, including genomics, transcriptomics, and proteomics, have facilitated detailed analysis of fungal metabolism, uncovering novel secondary metabolites and enzymatic pathways activated under specific growth conditions. This review highlights the potential of fungal coculture systems to advance sustainable biomass conversion in alignment with circular bioeconomy goals. Full article

Excessive tillage and chemical fertilization are the primary attributes of conventional farming and the main causes of soil degradation. This research focused on the comparative study of two tillage systems: conventional (CT) and no-tillage (NT), as well as on the effect of chemical fertilizers and different Bacillus megaterium var. phosphaticum inoculum rates (75, 100 and 125%) on soil properties. This short-term experiment was conducted under field conditions in Northeastern Romania from 2023 to 2024. Soil dehydrogenase, catalase, acid, and alkaline phosphatase activities, pH, organic carbon content (SOC), total nitrogen (TN), total phosphorus, and available phosphorus (TP and AP) were determined. Bacillus treatments generally inhibited soil enzyme activity by 0.35 to 57%, depending on the enzyme type. Under NT, activity increased by up to 59% for dehydrogenase, 43% for acid phosphatase, and 70% for alkaline phosphatase compared to the CT system. An opposite trend was found for catalase, along with a negative correlation with the other enzymes. There were positive differences in TP concentration at 125% Ecofertil + N in both CT (0.0577 ppm) and NT (0.0578 ppm) in 2023 compared to the control (0.0346–0.0374 ppm). In the same year, after the first inoculation, AP increased significantly with bacterial treatments in CT, from 32.34% (T0) to 47.94% (T4), and at crop harvest in NT in 2024, from 34.18% (T0) to 91.06% (T3). The results suggest that enzymatic activities and soil chemical properties were more influenced by soil management than the interaction between inoculated bacteria and chemical fertilizers. Full article

Laccase catalyzes one-electron oxidation, producing water as the primary final product, thereby minimizing secondary environmental pollution. Consequently, it holds significant application potential in areas such as the degradation of toxic compounds. In this study, a high-laccase-producing Trichoderma strain was isolated from soil, and the conditions for laccase production were optimized. Additionally, the laccase-related gene was cloned, and its function was analyzed. The results revealed that the optimal conditions for laccase production in this strain were maltose as the carbon source, peptone as the nitrogen source, an optimal pH of 6.0, and an incubation time of 120 h, resulting in an enzyme activity of 1.32 U/mL. The purified enzyme exhibited a Michaelis constant (K_m) of 0.06666 mmol/L when ABTS was used as the substrate. SDS-PAGE analysis indicated that the enzyme’s molecular weight was approximately 70 kDa. Sequencing of the target protein band led to the identification of the laccase-related gene Tasla01. Knockout of this gene resulted in the loss of laccase activity. We isolated a high-laccase-producing Trichoderma asperellum strain, Tasjk65, and cloned the laccase-related functional gene Tasla01. These findings lay a foundation for the source and application of laccase. Full article

Sediments are important repositories for microplastics (MPs) which exhibit higher microbial community richness and greater diversity than corresponding aqueous phases. Recently, the effects of MPs on microorganisms in sediments have received widespread attention. This review summarizes current knowledge on how MPs alter microbial diversity, composition, function, and biogeochemical cycling in sedimentary environments. The impacts of MPs on microorganisms in sediments can be affected by several factors, including MP type, the sedimentary environment, exposure time, and exposure concentration. Generally, biodegradable MPs cause more significant changes to the microbial community structure in sediments due to degradability and high bioavailability. Short-term exposure to MPs may enhance microbial diversity, and long-term exposure may lead to a reduction in diversity. High concentrations cause more serious impacts on microbial diversity than low concentrations. MPs mainly interfere with cycles of carbon, nitrogen, phosphorus, and sulfur in the sedimentary environment by changing microbial community structure, enzyme activity, and gene abundance. In conclusion, key research gaps are pinpointed, and future research directions presented. This review provides valuable insights into the health risks and ecological responses of MPs in sedimentary environments. Full article

The monoculture planting in terraced tea plantations has led to severe soil degradation, which poses a significant threat to the growth of tea plants. However, the mechanisms by which intercropping systems improve soil health through the regulation of soil microbial communities at the micro-topographical scale of terraced tea plantations (i.e., terrace surface, inter-row, and terrace wall) remain unclear. This study investigates the effects of intercropping Ophiopogon japonicus in a five-year tea plantation on the soil physicochemical properties, enzyme activities, and microbial community structure and functions across different micro-topographical features of terraced tea plantations in Wuyi Mountain. The results indicate that intercropping significantly improved the soil organic matter, available nutrients, and redox enzyme activities in the inter-row, terrace surface, and terrace wall, with the effects gradually decreasing with increasing distance from the tea plant rhizosphere. In the intercropping group, tea leaf yield increased by 13.17% (fresh weight) and 19.29% (dry weight) compared to monoculture, and the disease indices of new and old leaves decreased by 40.63% and 38.7%, respectively. Intercropping strengthened the modularity of bacterial networks and the role of stochasticity in shaping bacterial communities in different micro-topographic environments, in contrast to the patterns observed in fungal communities. The importance of microbial phyla such as Proteobacteria and Ascomycota in different micro-topographical features was significantly regulated by intercropping. In different micro-topographical zones of the terraced tea plantation, beneficial bacterial genera such as Sinomonas, Arthrobacter, and Ferruginibacter were significantly enriched, whereas potential fungal pathogens like Nigrospora, Microdochium, and Periconia were markedly suppressed. Functional annotations revealed that nitrogen cycling functions were particularly enhanced in inter-row soils, while carbon cycling functions were more prominent on the terrace surface and wall. This study sheds light on the synergistic regulatory mechanisms between micro-topographical heterogeneity and intercropping systems, offering theoretical support for mitigating soil degradation and optimizing management strategies in terraced tea agroecosystems. Full article

Substrate type exerts a critical influence on the growth, development, and nutritional quality of Auricularia heimuer. In this study, agricultural waste-derived corncob was used as the treatment group (T1), with sawdust serving as the control (CK), to systematically investigate the variation in free amino acid (FAA) content and transcriptomic expression profiles in fruiting bodies of A. heimuer under the two substrate conditions. Principal component analysis (PCA) revealed a clear separation between CK and T1 samples in terms of FAA composition, indicating that substrate type significantly affects FAA profiles. The corncob substrate notably increased the total FAA content in A. heimuer (2624.57 mg/kg), representing an 11.4% elevation compared to the sawdust group (2355.86 mg/kg), and markedly enhanced the proportion of flavor-associated amino acids (49.2% vs. 42.6%). In particular, the umami amino acid content was 74% higher than in the CK group. Transcriptome analysis identified 20 differentially expressed genes associated with FAA biosynthesis and degradation, including key enzymes involved in umami amino acid metabolism, such as aspartate decarboxylase (ADC), glutamate decarboxylase (GAD), and glutamate N-acetyltransferase (GNA), which were downregulated in T1. This suggests that glutamate and aspartate may have accumulated due to suppressed catabolism. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis further indicated that the differentially expressed genes were significantly enriched in pathways related to branched-chain amino acid metabolism, carbon metabolism, and secondary metabolism. Collectively, these findings demonstrate that corncob substrate significantly alters the accumulation and metabolic profile of FAAs in A. heimuer by modulating the expression of key metabolic enzymes, providing a theoretical foundation for the efficient cultivation of A. heimuer using agricultural waste and for enhancing its flavor quality. Full article

To address soil degradation risk caused by the long-term application of organic and nitrogen fertilizers in facility vegetable fields, this study selected soils with cumulative cultivation durations of 1, 3, 6, and 9 years to investigate the impact of organic and nitrogen fertilizer (OFN) application ratios on soil microbial community structure, greenhouse gas emissions, and enzyme activities. The results show that SOC content increases with soil cultivation duration and the proportion of organic fertilizer applied. Organic fertilizer stimulates urease and catalase activities; however, NH₄⁺-N in the soil inhibits enzyme activities. Organic fertilizer increases the abundance of Proteobacteria and Bacteroidota, enhancing its potential carbon sequestration capacity and also resulting in higher CH₄ and CO₂ emissions. The microbial community structure is influenced by both fertilizer ratios and soil cultivation duration. As the taxonomic level becomes finer, the number of differential species at the phylum (3), class (3), order (6), family (8), and genus (8) levels increases. The highest Chao1 index in soils of 1, 3, 6, and 9 years was observed at 0%, 25%, 50%, and 75% organic fertilizer substitution ratios, respectively. The 25% organic fertilizer substitution ratio showed better microbial diversity and evenness in 3-, 6-, and 9-year-old soils. Full article

Soil organic carbon (SOC) and total nitrogen (TN) sequestration are vital for maintaining soil fertility and mitigating climate change. This study aimed to evaluate the effects of different amendments (chemical and biological) and crop rotations on SOC, TN sequestration, and soil aggregate distribution. A six-year field study was conducted, involving five different treatments: a monoculture of peanut (PC), a monoculture of maize (MC), a maize-peanut rotation (M-PR), and peanut continuous cropping with chemical (PCCA) and biological (PCBA) amendments. Soil properties, aggregate size distribution, SOC, TN, and enzyme activities were measured. The results show that the bulk density increased, while the field water−holding capacity and porosity decreased with depth. M-PR had the highest macroaggregate (>0.25 mm) proportion, increasing by 21.6–50.8%. SOC and TN increased with aggregate size and were 23.9–103.6% and 7.0–82.9% higher, than PC and MC, respectively, under the treatments. PCCA showed the highest SOC, TN, and enzyme activities. Structural equation modeling indicated that the C and N contents of aggregates directly influenced SOC and TN sequestration. In conclusion, crop rotation and amendments, especially PCCA, effectively improve soil C and N sequestration, and enhance the soil structure, thereby reducing degradation risks, and potentially decreasing on−farm greenhouse gas emissions. Full article

Desertification, which may lead to land degradation, is a significant global ecological issue. Biological soil crusts (BSCs) can play a role in sand fixation, carbon sequestration, and the improvement in soil functions in the ecological restoration of sandy soil. Therefore, elucidating the responses of BSCs to afforestation measures in alpine sandy areas is necessary to guide vegetation configuration in sandy ecosystems and enhance the effectiveness of sand fixation measures to prevent desertification. Herein, we determined the physicochemical properties and enzyme activities of bare sand (no crust) and algal and moss crusts collected from four sites subjected to different afforestation measures, including Salix cheilophila + Populus simonii (WLYY), Salix psammophila + S. cheilophila (SLWL), Artemisia ordosica + Caragana korshinskii (SHNT), and C. korshinskii (NT80) plantations. High-throughput sequencing was also employed to analyze bacterial community structure in BSCs. The results revealed that fine particle contents in algal and moss crusts were higher than in bare sand. During the succession from bare sand to algae to moss crust, their enzymatic activities and water and nutrient contents tended to increase. And the diversity of bacterial communities changed little in the SLWL sample points, while the richness showed a trend of first decreasing and then increasing, but bacterial community richness and diversity first decreased and then increased at the other sites. Among the four measures, SLWL enhanced nutrient contents, enzyme activities, and bacterial community richness and diversity in BSCs relatively more effectively. Alkaline-hydrolyzable nitrogen and soil organic matter were the key factors impacting bacterial community structures in BSCs under the four afforestation measures. From the perspective of BSCs, the results can provide a reference for the prevention and control strategies of other alpine sandy soils. Full article

The need for sustainable and efficient water decontamination methods has led to the increasing use of redox enzymes such as glucose oxidase (GOx). GOx immobilization on textile supports provides a promising alternative for catalyzing pollutant degradation in bio-Fenton (BF) and bio-electro-Fenton (BEF) systems. However, challenges related to enzyme stability, reusability, and environmental impact remain a concern. This communication paper outlines innovative strategies developed to address these challenges, notably the use of ecotechnologies to achieve efficient GOx immobilization while maintaining biocatalytic activity. Plasma ecoprocesses, amino-bearing biopolymer-chitosan, as well as a bio-crosslinker genipin have been used efficiently on conductive carbon and non-conductive polyester-PET nonwovens. In certain cases, immobilized GOx can retain high catalytic activity after multiple cycles, making them an effective biocatalyst for organic dye degradation (Crystal Violet and Remazol Blue) via bio-Fenton reactions, including total heterogeneous bio-Fention system. Moreover, the conductive carbon felt-based bioelectrodes successfully supported simultaneous pollutant degradation and energy generation in a BEF system. This work highlights the potential of textile-based enzyme immobilization for sustainable wastewater treatment, bio-electrochemical energy conversion, and also for bacterial deactivation. Future research will focus on optimizing enzyme stability and enhancing BEF efficiency for large-scale applications. Full article

The increasing global population and intensifying resource limitations present a formidable challenge for sustainable crop production, especially in developing regions. This review explores the pivotal role of microbial ecosystem services in alleviating environmental stresses that impede agricultural productivity. Soil microbiota, particularly plant growth-promoting microbes (PGPMs), are integral to soil health and fertility and plant resilience against both abiotic (drought, salinity, temperature extremes, heavy metals) and biotic (pathogen) stresses. These microorganisms employ a variety of direct and indirect mechanisms, including the modulation of phytohormones, nutrient solubilization, the production of stress-alleviating enzymes, and the synthesis of antimicrobial compounds, to enhance plant growth and mitigate adverse environmental impacts. Advances in microbial biotechnology have expanded the toolkit for harnessing beneficial microbes, enabling the development of microbial inoculants and consortia tailored for specific stress conditions. This review highlights the multifaceted contributions of soil microbes, such as improving nutrient uptake, promoting root development, facilitating pollutant degradation, and supporting carbon sequestration, all of which underpin ecosystem resilience and sustainable agricultural practices. Furthermore, the synergistic interactions between plant roots and rhizospheric microbes are emphasized as key drivers of soil structure enhancement and long-term productivity. By synthesizing current research on the mechanisms of microbe-mediated stress tolerance, this review underscores the potential of microbial interventions to bridge the gap between food security and environmental conservation. The integration of microbial solutions into agroecosystems offers a promising, eco-friendly strategy to revitalize soils, boost crop yields, and ensure agricultural sustainability in the face of mounting environmental challenges. Full article