Search Results (219)

In recent years, most of the populations of the world have been using herbal materials for their strong antimicrobial properties and major health benefits. The objective of this study was to evaluate the phenolic profile, as well as the antioxidant and antimicrobial activities, of a dietary supplement composed of extracts from hibiscus (Hibiscus sabdariffa L.) calyces and lemon verbena (Lippia citriodora) leaves (Metabolaid^®, Patent P201731147) mixed at a weight ratio of 35:65 (w/w), respectively. The bioactive components of the methanolic extract were analyzed by UHPLC-ESI-MS/MS. The antioxidant activity was evaluated using spectrophotometric methods, while the antimicrobial activity was assessed through the microdilution method against selected Gram-negative and Gram-positive bacteria. The total phenols content resulted in being 256.10 ± 2.26 mg GAE/g f.w., the flavonoid content was 48.90 ± 2.95 mg CE/g f.w., flavonols were 60.17 ± 7.68 mg QE/g f.w., and anthocyanins were 3.78 ± 0.17 mg C3GE/g f.w. The FRAP value, observed in the natural mix additive, was 1.25 ± 0.03 mg Fe²⁺/g f.w., while the ORAC showed the value of 1893.77 ± 30.39 µmol TE/g f.w. and the DPPH was 23.33 ± 4.12 µg/mL. We found eight phenolic acids, seven flavonols, five anthocyanins, and nine other phenolic compounds. The extract showed a minimum inhibitory concentration (MIC) of 12.5 mg/mL against E. coli, E. aerogenes, and E. faecalis and of 25 mg/mL against S. enterica ser. Typhimurium and S. aureus and a minimum bactericidal concentration (MBC) of 25 mg/mL against E. coli, E. aerogenes, and E. faecalis and of 50 mg/mL against S. enterica ser. Typhimurium and S. aureus. In conclusion, our findings demonstrate that Metabolaid^® is a rich source of bioactive compounds and provides beneficial effects against oxidative stress and pathogenic bacteria, supporting its nutraceutical potential. Full article

The increasing threat of antimicrobial resistance (AMR), along with the limited availability of new lead compounds in the drug development pipeline, highlights the urgent need to discover antimicrobial agents with innovative mechanisms of action. In this regard, metal complexes offer a unique opportunity to access mechanisms distinct from those of conventional antibiotics. Although iron (Fe) is an essential element for all forms of life, including pathogenic bacteria, it also poses a serious risk of cytotoxicity due to its redox activity, which can trigger the production of reactive oxygen species (ROS) via the Fenton reaction. This review highlights recent advances in the development of iron-based antimicrobial agents that harness the toxicity resulting from dysregulated iron uptake, thereby inducing bacterial cell death through oxidative stress. These findings may guide the development of effective treatments for pathogenic infections and offer new perspectives on leveraging redox chemistry of iron to combat the growing threat of global bacterial resistance. Full article

Background/Objectives: Lactobacillus johnsonii CRL1231 (Lj CRL1231) is a strain with feruloyl esterase (FE) activity that enhances ferulic acid (FA) release from wheat bran (WB) and has potential as a probiotic for metabolic syndrome (MS). Given the potential health benefits of FA and its microbial metabolites, this study aimed to evaluate the therapeutic effect of Lj CRL1231 co-administered with WB in a mouse model of metabolic syndrome (MS) induced by a high-fat diet (HFD). Methods: Mice were divided into three groups and fed for 14 weeks as follows: the Control group (standard diet), the MS group (HFD+WB), and the MS+Lj group (HFD+WB and Lj CRL1231-dose 10⁸ cells/day). Specifically, we analyzed the changes in the intestinal microbiota (IM), colonic FE activity, generation of FA-derived and fermentation metabolites, and metabolic and inflammatory parameters. Results: Improvements in the MS+Lj group compared to the MS group included the following: a—a 38% increase in colonic FE activity, leading to elevated levels of FA-derived metabolites (e.g., dihydroferulic, dihydroxyphenylpropionic, and hydroxyphenylpropionic acids); b—a significant shift in the IM composition, with a 3.4-fold decrease in Firmicutes and a 2.9-fold increase in Bacteroidetes; c—a decrease in harmful bacteria (Desulfovibrio) by 93%, and beneficial bacteria like Bifidobacterium increased significantly (6.58 log cells/g); d—a 33% increase in total SCFAs; e—a 26% reduction in the adiposity index; f—a 12% increase in HDL cholesterol and a 19% reduction in triglycerides; g—normalized glucose and insulin resulting in a 2-fold lower HOMA-IR index; h—an improved inflammatory profile by decreasing TNF-α, IFN-γ, and IL-6 (3-, 5-, and 2-fold, respectively) and increasing IL-10 by 2-fold; i—alleviation of liver damage by normalizing of transaminases AST (19.70 ± 2.97 U/L) and ALT (13.12 ± 0.88 U/L); j—evidence of reduced oxidative damage. Conclusions: The co-administration of L. johnsonii CRL1231 and WB exerts a synergistic effect in mitigating the features of MS in HFD-fed mice. This effect is mediated by modulation of the gut microbiota, increased release of bioactive FA-derived compounds, and restoration of metabolic and inflammatory homeostasis. This strategy represents a promising dietary approach for MS management through targeted microbiota–metabolite interactions. Full article

The bioavailability of heavy metals is profoundly influenced by their interactions with active soil components (microorganisms, organic matter, and iron minerals). However, the effects of urease-producing bacteria combined with organo-Fe hydroxide coprecipitates (OFCs) on Cd accumulation in wheat, as well as the mechanisms underlying these effects, remain unclear. In this study, pot experiments integrated with high-throughput sequencing were employed to investigate the impacts of the urease-producing bacterial strain TJ6, ferrihydrite (Fh), and OFCs on Cd enrichment in wheat grains, alongside the underlying soil–microbial mechanisms. The results demonstrate that the strain TJ6-Fh/OFC consortium significantly (p < 0.05) reduced (50.1–66.7%) the bioavailable Cd content in rhizosphere soil while increasing residual Cd fractions, thereby decreasing (77.4%) Cd accumulation in grains. The combined amendments elevated rhizosphere pH (7.35), iron oxide content, and electrical conductivity while reducing (14.5–21.1%) dissolved organic carbon levels. These changes enhanced soil-colloid-mediated Cd immobilization and reduced Cd mobility. Notably, the NH₄⁺ content and NH₄⁺/NO₃⁻ ratio were significantly (p < 0.05) increased, attributed to the ureolytic activity of TJ6, which concurrently alkalinized the soil and inhibited Cd uptake via competitive ion channel interactions. Furthermore, the relative abundance of functional bacterial taxa (Proteobacteria, Gemmatimonadota, Enterobacter, Rhodanobacter, Massilia, Nocardioides, and Arthrobacter) was markedly increased in the rhizosphere soil. These microbes exhibited enhanced abilities to produce extracellular polymeric substances, induce phosphate precipitation, facilitate biosorption, and promote nutrient (C/N) cycling, synergizing with the amendments to immobilize Cd. This study for the first time analyzed the effect and soil science mechanism of urease-producing bacteria combined with OFCs in blocking wheat’s absorption of Cd. Moreover, this study provides foundational insights and a practical framework for the remediation of Cd-contaminated wheat fields through microbial–organic–mineral collaborative strategies. Full article

Lulo or naranjilla (Solanum quitoense Lam.) is an Andean fruit with a sour and refreshing flavor, widely used in the preparation of juices and sweets. Despite its potential for international markets, it remains largely unknown outside its native regions, and most existing studies have focused on the whole fruit or its juice. This study investigated the nutritional and phenolic profiles of the peel, pulp, and seeds of S. quitoense using official food analysis methods and chromatographic techniques. In addition, the in vitro antioxidant activity and antimicrobial effects against foodborne fungi and bacteria were assessed. The peel was rich in ascorbic acid (25.2 mg/100 g fw), α-tocopherol (7.9 mg/100 g fw), dietary fiber (16.5 g/100 g fw), macrominerals (Na, Ca, K), and flavonoids (14.2 mg/g extract); the pulp contained high levels of citric acid (4.22 g/100 g fw) and sucrose (2.7 g/100 g fw); and the seeds stood out for their contents of trace elements (Zn, Cu, Mn, Fe), oleic acid, and spermidine-derived phenolamides (37.8 mg/g extract). Hydroethanolic extracts showed antioxidant activity by inhibiting lipid peroxidation and oxidative hemolysis, with the seed extract exhibiting the strongest antifungal effect against Aspergillus versicolor, likely due to its high spermidine derivative content. These findings shed light on the potential of S. quitoense fruit for the development of functional foods, antioxidant-rich beverages, and nutraceutical products. Full article

The quality of strong-flavor baijiu largely depends on the physicochemical properties and prokaryotic microbial activities of pit mud. However, the impact of the iron-bearing minerals in pit mud on its prokaryotic microbial communities remains unknown. This study examined the differences in the prokaryotic communities between 2-year, 40-year, and 100-year pit mud and yellow soil (the raw material for pit mud), as well as the impacts of environmental factors, particularly iron-bearing minerals, on the structure and diversity of these prokaryotic communities. The results indicated that there were significant differences in the composition of prokaryotic microorganisms between yellow soil and pit mud. As the fermentation pit aged, the relative abundance of dominant fermentation bacteria (including Petrimonas, Syntrophomonas, Clostridium, etc.) and hydrogenotrophic methanogens in the pit mud increased. The relative abundance of Lactobacillus in the 2-year pit mud was low (0.33%). Under laboratory conditions, goethite (a typical crystalline iron mineral, denoted as Fe_c) reduced the physiological and metabolic activity of Lacticaseibacillus paracasei JN01 in a concentration-dependent manner. The results of the physicochemical analysis showed that the contents of total iron (TFe) and Fe_c significantly decreased, while the contents of Fe(II) and amorphous iron (hydr)oxides (Fe_o) significantly increased with an increasing fermentation pit age. TFe and Fe_c were significantly negatively correlated with both the Chao1 and Shannon indexes and functional microorganisms such as Clostridium_sensu_stricto_12, Sedimentibacter, and hydrogenotrophic methanogens. The current results contribute to our understanding of the aging process of pit mud from the perspective of the interaction between iron-bearing minerals and prokaryotic microorganisms. Full article

Background/Objectives: Thrombotic diseases (TDs), currently the number one killer worldwide, account for the highest mortality rate globally. In this study, we evaluated the antithrombotic efficacy of Velefibrinase, a marine bacteria-derived fibrinolytic enzyme, across multiple animal models. Results: The results demonstrated that Velefibrinase prolonged bleeding time (BT) and clotting time (CT), reduced mortality and thrombosis, relieved pulmonary alveolar structure degeneration in an acute pulmonary thromboembolism model, and inhibited carotid artery thrombosis and endothelial tissue damage in a rat model of FeCl₃-induced carotid arterial thrombosis. Moreover, Velefibrinase reduced cerebral ischemia volume and ameliorated neurological deficits in a cerebral ischemia/reperfusion (I/R) injury model in rats. The putative underlying mechanisms were found to involve the inhibition of platelet aggregation and coagulation, along with the modulation of oxidative stress and inflammation levels. Conclusions: These results revealed that Velefibrinase exerts a notable thrombosis-preventive effect by interacting with multiple targets, thereby breaking the vicious cycle involving inflammation, oxidative stress, and thrombosis. Full article

Few studies have addressed the coupling of arsenic (As) and nitrogen (N) geochemistry in natural soil. This research focused on the vertical distribution and coupling behavior of As and N in coastal wetland sediments. Pore water and sediment from barren wetlands and coastal wetlands near three estuaries (Guanhe River, Sheyang River, and Liangduo River) in central Jiangsu Province of China with Spartina alterniflora (S. alterniflora) were sampled, which were analyzed for total As content and speciation and N inorganic fractions. The bacterial community was investigated through 16s rDNA sequencing; diversity indices were calculated. The As change trend in pore water of surface sediment with increasing depth was opposite to that of NO₃⁻, possibly because NO₃⁻ promoted arsenite (As(III)) oxidation to arsenate (As(V)). Increased NO₃⁻ contents seemed to mitigate As toxicity. The vertical distribution of NH₄⁺ indicated anaerobic ammonium oxidation and iron (Fe) ammonium oxidation to reduce Fe oxides, resulting in As release, especially in the deeper sediment. High-throughput sequencing analysis revealed some potential bacteria possibly involved in As-N geochemical coupling, such as Bacillus and Psychrobacter, which can couple denitrification with As oxidation, and Sva1033, which may favor ammonium oxidation-induced As release. Our results suggest that the N-driven oxidation of As(III) and the ammonium oxidation-induced As release can be relevant to As-N coupling processes in the coastal wetland and emphasize the importance of microorganisms in such processes. This research deepens our understanding of As-N coupling in natural coastal wetlands, providing a theoretical basis for controlling As pollution. Full article

Tannic acid (TA), a prevalent polyphenolic contaminant in industrial effluents, significantly inhibits microbial activity in anaerobic digestion, thereby diminishing wastewater treatment efficiency. In this study, a sulfidized nano zero-valent iron (S-nZVI) composite incorporated into sludge biochar (SB), abbreviated as SB-S-nZVI, was synthesized via a one-step hydrothermal method. The composite’s adsorption capacity for TA and its impact on anaerobic digestion were systematically evaluated. Experimental results showed that SB-S-nZVI achieved a TA removal efficiency of 99.31% under optimal conditions (S/Fe = 0.05, dosage = 0.3 g·L⁻¹), with a maximum adsorption capacity of 337.08 mg·g⁻¹. In anaerobic digestion, the addition of 0.03 g·L⁻¹ SB-S-nZVI enhanced chemical oxygen demand (COD) removal by 3.32%, increased specific methanogenic activity by 62.66%, and improved the microbial community composition, particularly enriching hydrolytic bacteria (Georgenia) and methanogenic archaea (Methanosaeta). The mechanistic analysis revealed that the FeS protective layer of SB-S-nZVI inhibited nano zero-valent iron oxidation and facilitated chemisorption-driven TA removal. This study presents an innovative approach for the integrated treatment of TA-contaminated wastewater by combining adsorption, degradation, and energy recovery. Full article

Microbiologically influenced corrosion (MIC) is one of the key causes of material failure in marine engineering, and sulfate-reducing bacteria (SRB) and iron-oxidizing bacteria (IOB) are typical representatives of anaerobic and aerobic microorganisms, respectively. These microorganisms are widely present in marine environments and can form synergistic communities on the surface of metal materials, posing a corrosion threat to them. At the same time, the presence of mixed bacteria may have an effect on cathodic protection, so this study investigates the growth metabolism of mixed SRB and IOB under different cathodic protection potentials in an impressed current cathodic protection (ICCP) system in a marine environment containing SRB and IOB. It also examines the attachment of these microorganisms to the anode and cathode, and the impact on cathodic protection efficiency. The results indicate that in a marine environment containing IOB and SRB, the cathodic protection efficiency of the ICCP system increases with the negative shift of the protection potential. A more positive cathodic protection potential promotes the adhesion of mixed bacteria on the electrode surface and the formation of a biofilm, which reduces cathodic protection efficiency. In contrast, at a cathodic protection potential of −1.05 V (SCE), bacterial growth is inhibited, and a dense crystalline corrosion film primarily composed of Fe₂O₃ and Fe(OH)₃ forms on the cathode surface. This film effectively protects the cathodic metal, significantly mitigating MIC. Full article

The growing threat of bacterial resistance, coupled with the increasing costs associated with drug development, poses significant challenges in the discovery of new antibiotics. The present study reports the synthesis and antimicrobial evaluation of 1,4-dihydropyridine (1,4-DHP) derivatives derived from chalcones, using silica-mediated magnetic iron oxide, Fe₂O₃@SiO₂ nanoparticles as a nanocatalyst. The nanoparticles were characterized using FT-IR, SEM-EDS, XRD, Zeta-Potential, and VSM techniques to confirm their structure and properties. Among them, the series 8a–e (particularly compound 8c) demonstrated strong antimicrobial activity, with effectiveness comparable to standard drugs Fluconazole and Amoxicillin; this was attributed to the presence of polar groups. Other derivatives exhibited moderate activity, with MICs ranging from 25 to 50 μg/mL, while no significant activity was observed against Gram-negative bacteria. These compounds hold potential as promising antimicrobial agents and warrant further investigation for the development of effective therapies. Full article

This study presents the effectiveness of two vertical subsurface flow (VF) constructed wetlands (CWs), one planted with Juncus effusus (PCW) and the other unplanted (CCW), for the remediation of acid mine drainage (AMD) from the Ouixane abandoned mine site located in Morocco. The VFs were fed with highly acidic AMD (pH < 2.5) and were evaluated over a period of 150 days. The substrate was composed of limestone, as a neutralizing agent, river gravel, and natural peat moss, with the goal of promoting the growth of sulfate-reducing bacteria (SRB) and metals precipitation. The results showed that both VFs successfully neutralized the acidity, with effluent pH values ranging from 3.57 to 8.5, indicating effective alkalinization of the AMD. Significant differences (p < 0.05) were observed between the metal removal rates of the CCW and the PCW, except for Mn. Both types of constructed wetlands (CWs), the planted system (PCW) and the unplanted system (CCW), exhibited similar efficiencies in metal removal from the influent. The rates of metalloid removal were as follows: 99.9% vs. 99% for Cr, 99% vs. 80% for As, 96% vs. 94 for Zn, 99.94% vs. 99% for Fe, and 90% vs. 81% for Al. Microbial sulfate reduction was increased from 43% to 50% by the presence of plants. Sediment analysis revealed that metals were primarily in stable forms: Fe and Zn were mostly associated with Fe-Mn oxides, while Mn and Ni were predominantly present as carbonates. These observations indicate a relative stability of metals in the CWs’ sediment. This study highlights the effectiveness of the studied CWs, particularly those with vegetation, for AMD remediation, emphasizing the importance of neutralizing agents, plants, and organic substrates in the treatment process. Full article

The present study aimed to evaluate the effects of incorporating different concentrations (1% and 2%) of Malvaviscus arboreus flower (FE) and leaf (LE) extracts as functional ingredients in goat milk yogurt. This study analyzed the impact of these formulations (YFE1%, YFE2%, YLE1%, and YLE2%) on the physicochemical, bioactive, antioxidant, rheological, textural, and sensory properties of goat yogurt over a 28-day storage period. Including FE and LE extracts significantly enhanced the yogurt’s antioxidant activity, reaching up to 10.17 µmol TEAC/g, and strengthened its ability to inhibit lipid oxidation during storage. This study also observed a reduction in the viability of lactic acid bacteria, particularly L. delbrueckii subsp. bulgaricus, suggesting that the extracts may have antimicrobial properties. Notably, using FE, especially at a concentration of 2% (YFE2%), improved both antioxidant and textural properties while reducing syneresis by the end of the storage period. Sensory evaluations showed positive results for YFE1% and YFE2% formulations. These findings suggest that FE has significant potential as a functional food ingredient. This research lays the groundwork for future studies exploring the integration of Malvaviscus arboreus-based ingredients into functional food products, opening new possibilities for innovation in this field. Full article

A green and cost-effective sonochemical synthetic method was followed for coating silver-modified copper oxide (Ag-CuO) nanoparticles (NPs) on disposable surgical mask. The NP-coated masks were systematically characterized using XRD and FT-IR for understanding the structural and surface functionalities. In addition, the field emission scanning electron microscopy (FE-SEM) analysis showed the homogeneous coating of Ag-CuO NPs over the mask fibers. The average particle size of Ag-CuO was found to be ~70 nm. The NP-coated masks are useful to combat a broad range of bacterial species by taking the unique advantage of the synergistic effect of Ag and metal oxide (CuO and ZnO) NPs for the generation of reactive oxygen species (ROS). Zone of inhibition (ZoI) studies demonstrated antibacterial activity against both Gram-positive S. aureus and Gram-negative E. coli bacteria, probably due to the elevated production of ROS by the defect structure of the Ag-modified metal oxide NPs. The material was found to be effective against both airborne and soil-borne bacteria. We repeat that this paper deals only with the killing effect of the nanoparticles (Ag-modified CuO) on bacteria, and no studies on viral species are performed. Full article

Feammox, one of the potential pathways for nitrogen loss in the environment, plays an essential role in nitrogen cycling and provides new ideas for the biological denitrification of wastewater. However, the Feammox reaction has low nitrogen removal efficiency and stagnates due to insufficient Fe(III) sources. It strongly depends on an Fe(III) source supply, significantly limiting its development. In this study, a synergistic nitrogen removal system using Feammox and Nitrate-Dependent Fe(II) Oxidation (NDFO) driven by NO₃⁻-N was constructed within an organic carbon environment. It uses the synergy between Feammox and NDFO to improve nitrogen removal. The removal efficiency of NH₄⁺-N reaches over 70% in stages III-V, with a maximum removal efficiency of 89.4%. NH₄⁺-N oxidation and Fe(III) reduction are positively coupled in the Feammox reaction. The Fe(II)/Fe(III) cycle process driven by Feammox and NDFO improves the utilization of the iron source, thus guaranteeing the sustainability of the NH₄⁺-N oxidation reaction. In addition, the organic carbon environment also enriched NDFO bacteria (Thermomonas and Acinetobacter) and increased the reaction rate of NDFO, which enhanced the transformation of Fe(II). We improved the nitrogen removal efficiency of Feammox and provided a new approach for nitrogen removal in wastewater treatment. Full article