Search Results (171)

Green nanotechnology is now well established, showcasing how natural precursors can replace hazardous synthesis routes. This review analyzes the diverse biotechnological applications of biogenic nanomaterials. In the biomedical field, they have demonstrated significant efficacy as antimicrobial agents, targeted drug delivery vehicles, wound healers, and theragnostic platforms. They also enhance food packaging security, optimize nano-fertilizers, and control insect pests. Additionally, their unique surface properties and catalytic activity make them key candidates for pollutant remediation and advanced chemical sensors. Ultimately, while green nanoparticles offer clear advantages over traditional chemical methods, key bottlenecks, like batch-to-batch reproducibility, industrial scalability, and long-term ecotoxicological and multigenerational impacts, still need to be addressed. Full article

Chronic wounds are complex environments marked by persistent inflammation, oxidative stress, hypoxia, and conditions that favor antimicrobial resistance (AMR). Conventional antibiotics often fail due to bacterial persistence and the physicochemical barriers of the wound milieu. Biofilm-associated extracellular polymeric substances (EPS), efflux pump activity, quorum sensing (QS), and horizontal gene transfer (HGT) collectively drive antimicrobial tolerance and resistance dissemination, turning chronic wounds into reservoirs of multidrug-resistant pathogens. Consequently, emerging wound therapies demand multifunctional strategies that modulate the wound microenvironment while interfering with resistance-associated phenotypes. Hydrogel–metal–organic framework (MOF) composites have been explored as multifunctional interfaces that combine extracellular matrix-mimetic properties, tunable porosity, stimuli-responsiveness, and controlled therapeutic delivery with the bioactive functions of MOFs. Depending on their composition and architecture, these systems may exert antimicrobial and antibiofilm effects through ionic, electrostatic, osmotic, catalytic, and oxidative mechanisms, while also influencing ROS levels, inflammation, angiogenesis, and local drug transport. However, antimicrobial activity alone does not equate to resistance modulation. Evidence for direct effects on efflux systems, resistance phenotypes, or HGT remains inconsistent across reported platforms. This review critically examines representative hydrogel–MOF systems for chronic wound applications, comparing their composition, physicochemical properties, biological functions, proposed resistance-related mechanisms, advantages, limitations, and current level of evidence. We emphasize distinguishing experimentally demonstrated resistance-modulating effects from mechanistically proposed functions, and identifying design trade-offs and evidence gaps that must be addressed to develop wound interfaces capable of both supporting tissue regeneration and improving infection control. Full article

Potato peel waste (PPW) represents a low-cost and eco-friendly by-product with potential for use as a fermentation substrate for the production of antibacterial metabolites by Bacillus species. This study evaluated PPW as a fermentation matrix for Bacillus velezensis and demonstrated that 2% PPW supported optimal production of antibacterial compounds. The cell-free supernatant obtained after 96 h of fermentation exhibited the strongest activity against E. coli 18/22, with a MIC of 62.5 µg/mL. The ethyl acetate extract exhibited rapid bactericidal activity, killing E. coli 18/22 within 30 min at 2× MIC and within 120 min at MIC. The antibacterial activity remained stable up to 80 °C, across pH 4–12, and after treatment with pepsin and chymotrypsin. LC/HR-ESI-MS analysis identified oxydifficidin and surfactins C14 and C15 as the main active compounds. Molecular docking revealed that oxydifficidin and surfactin C15 exhibited the strongest binding affinity toward Shiga toxin II, while surfactin C14 displayed a weaker interaction, suggesting the role of acyl chain length in toxin binding. Both oxydifficidin and surfactins interacted with key residues within the catalytic pocket of the AcrB subunit of the AcrAB–TolC multidrug efflux pump, indicating potential inhibition of multidrug resistance mechanisms. To our knowledge, this is the first report describing the use of PPW as a fermentation substrate for Bacillus velezensis B38 to produce oxydifficidin and surfactin C14 and C15 exhibiting antimicrobial activity against multidrug-resistant E. coli. These findings provide a promising strategy for transforming agro-industrial waste into value-added antimicrobial metabolites, contributing to the circular bioeconomy strategies within the One Health framework. Full article

Precious metal nanoparticles (PMNPs), particularly silver, gold, palladium, and platinum nanoparticles, have attracted considerable attention owing to their unique physicochemical properties and broad applications in catalysis, environmental remediation, and biomedicine. Conventional physical and chemical synthesis methods often require substantial energy input, harsh reaction conditions, and generate large volumes of metal-containing wastewater, raising concerns regarding sustainability and environmental impact. Microbial synthesis provides a sustainable alternative by using microorganisms as natural biofactories to convert toxic precious metal ions into valuable nanoparticles under mild conditions. This review summarizes recent advances in the microbial synthesis of PMNPs (Bio-PMNPs), focusing on biosynthetic mechanisms in bacteria, algae, and fungi. Bio-PMNPs formation involves both extracellular and intracellular reduction processes, coupled with electron transfer mediated by reductases and other redox-active biomolecules. Functional groups present on microbial cell walls, as well as proteins, polysaccharides, enzymes, and other metabolites, play important roles in the adsorption, reduction, stabilization, and growth of nanoparticles. We further highlight the applications of Bio-PMNPs in antimicrobial activity, cancer therapy, pollutant degradation, heavy-metal removal, and catalytic enhancement of organic synthesis. Despite substantial progress, challenges remain in controlling nanoparticle size and morphology, elucidating biosynthetic mechanisms, and achieving large-scale production. Future integration of synthetic biology, metabolic engineering, and process optimization is expected to improve the controllability, stability, scalability, and biosafety of Bio-PMNPs production. Full article

Novel biogenic cobalt ferrite nanoparticles were prepared biologically using Adansonia digitata L. (Baobab) Fruit Pulp Extract, assisted by a microwave heating method. The utilization of Adansonia digitata L. (Baobab) Fruit Pulp Extract assisted by microwave heating is considered an eco-friendly method that is environmentally sustainable and inexpensive in terms of energy consumption and large-scale production. Different techniques were used to characterize plant extract-mediated nanoparticles, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N₂ adsorption–desorption analysis. The XRD analysis revealed single-phase crystalline structures with a mean size of 31.5 nm. In SEM and TEM studies, the nanoparticles took different morphologies, such as regular and spherical shapes. The bio-synthesized nanoparticles showed high removal efficiency as adsorbent components in MO removal, for example, of organic dye. The influences of different factors on the adsorption process, such as MO concentration, solution pH, and doses used, were tested based on the amount of adsorbent used. The kinetic and isotherm study results revealed that pseudo-second-order kinetics models and the Freundlich sorption isotherm model fit the adsorption process of MO on nano adsorbents well. Additionally, the antimicrobial assessment of CoFe₂O₄ NPs was tested against five species of human pathogenic bacteria, as well as one fungal species. The results show that CoFe₂O₄ NPs exhibit higher inhibition activity against the examined microorganisms. Full article

Background/Objectives: Salmonella enterica (S. enterica) is a major poultry-associated foodborne pathogen and a persistent public health concern. The global rise in antimicrobial resistance has accelerated the search for alternative control strategies, including the use of bacteriophages. However, their successful application requires a comprehensive evaluation of their biological performance, genomic safety, and functional proteins. This study aimed to characterize Salmonella phage WP110 and assess its potential as a biocontrol agent in broiler-associated production systems. Methods: Phage WP110 was evaluated against 251 S. enterica isolates from broiler-related sources. Adsorption kinetics, one-step growth, environmental stability (temperature and pH), and effective multiplicity of infection (MOI) were determined using Salmonella Kentucky S1H28. Whole-genome sequencing (WGS) and bioinformatic analyses were performed for genome annotation, taxonomic classification, and safety evaluation. In addition, protein structural prediction of a putative endolysin (WP110-gp057) was conducted using AlphaFold2, followed by structural comparison and molecular docking with peptidoglycan. Biocontrol efficacy was evaluated in contaminated rice husk, chicken meat, and on non-food materials. Results: Phage WP110 demonstrated a broad lytic spectrum, lysing 248/251 S. enterica isolates (98.8%). It adsorbed rapidly (within 3–15 min) to host cells and exhibited a latent period of ~20 min with a burst size of 134 particles per infected cell. Phage WP110 remained stable at 4–45 °C and pH 5–11 but was inactivated at ≥75 °C and pH 2. Complete bacterial inactivation in broth assay was achieved at an MOI of 10⁴. Genomic analysis revealed a 110,216 bp linear dsDNA genome (39.74% GC) comprising 204 ORFs, 25 tRNAs, and long direct terminal repeats, with no detectable antibiotic resistance genes. Phylogenetic and intergenomic analyses classified phage WP110 as a novel species within the genus Epseptimavirus. Structural modeling of WP110-gp057 revealed conserved catalytic residues and high structural similarity to T5 endolysin, while docking analysis supported a structurally plausible interaction with peptidoglycan at the predicted active-site groove, consistent with its proposed role in host cell wall degradation. In application models, phage WP110 significantly reduced Salmonella contamination in rice husk (up to 4.3 log CFU/g), chicken meat (up to 1.7 log CFU/g), and on non-food material surfaces (0.7–1.5 log CFU reduction). Conclusions: Phage WP110 is a broad-host-range lytic phage with favorable infection kinetics, environmental robustness, and genomic safety. Its functionally supported endolysin and strong antibacterial efficacy across broiler-associated matrices highlight its potential as a biocontrol agent for Salmonella mitigation in poultry value chain. Full article

Metal oxide nanoparticles have been the subject of intense research interest because of their remarkable physicochemical properties, such as their high surface area, particle size tunability, outstanding chemical stability, optical activity, catalytic efficiency, and antimicrobial behavior. These properties make them very useful in environmental, biomedical, energy, sensing, agricultural and industrial applications. The chosen synthesis method is important in controlling the morphology, crystallinity, surface charge, band gap and overall performance of metal oxide nanoparticles. They have been prepared using various physical, chemical and biological means, such as sol–gel, co-precipitation, hydro/solvothermal, microwave-assisted, sonochemical, combustion and green synthesis. Of these, green synthesis is gaining more interest as it employs plant extracts, microorganisms, and other biological materials as reducing agents, stabilizing and capping agents that make the process more eco-friendly and cost-effective. Recent advancements in the synthesis and application of metal oxide nanoparticles are discussed. There is an emphasis on the major synthesis routes, the main factors that influence the formation of nanoparticles, the characterization techniques used, and the structure–property relationships uncovered. A special focus is given to the influence of synthesis parameters, such as the type of precursor and the pH, temperature, reaction time, solvents and capping agents, on the properties of nanoparticles. In addition, the uses of metal oxide nanoparticles in photocatalysis, wastewater treatment, antimicrobial activity, drug delivery, biosensing, energy storage, gas sensing, and agriculture are also included. Finally, present challenges, toxicity issues, the problems of large-scale production, and future research directions are discussed to support the practical and sustainable uses of metal oxide nanoparticles. Full article

The emergence of antimicrobial resistance necessitates the development of structurally novel agents with improved biological profiles. In this study, a series of new derivatives of fluconazole were designed, synthesized, and evaluated for antifungal activity. The synthetic approach involved esterification of hydroxyl group of fluconazole with an azide-group-containing benzoyl chloride, followed by copper-catalyzed azide–alkyne cycloaddition (CuAAC). The optimized catalytic system was based on a copper(I) catalyst generated from copper(II) palmitate and ascorbic acid. The transformations of the azide-containing derivatives were then performed. The obtained compounds were tested against reference strains of clinically relevant Candida spp., including C. albicans ATCC 10231, C. parapsilosis ATCC 22019, C. krusei ATCC 14243, C. auris CDC B11903, C. tropicalis ATCC 1369, C. glabrata ATCC 15126, and C. lusitaniae ATCC 3449. Some of the obtained derivatives showed very low toxicity in the MTT-based cell viability assay while maintaining high antifungal activity against selected strains. Full article

Catalytic nanozymes have emerged as a versatile class of engineered nanomaterials that combine enzyme-like catalytic activity with exceptional physicochemical stability, tunable composition, and scalable fabrication, offering significant advantages over natural enzymes for antimicrobial applications in food systems. Recent advances in materials engineering have enabled the development of nanozymes with enhanced catalytic efficiency, broad-spectrum antimicrobial activity, and improved resistance to harsh food-processing environments. Nevertheless, current research remains fragmented across diverse material platforms and application scenarios, while a comprehensive understanding of how engineering strategies govern catalytic performance, antimicrobial efficacy, and translational potential is still lacking. This review provides a critical and systematic analysis of catalytic nanozymes for antimicrobial food systems from a structure–activity relationship perspective. Emphasis is placed on the engineering principles that regulate enzyme-mimicking activities, including compositional tuning, crystal phase and facet engineering, defect creation, heterostructure construction, pore architecture, surface functionalization, and single-atom engineering. The relationships between these structural features and catalytic mechanisms, including peroxidase-, oxidase-, catalase-, and multi-enzyme-like activities, are discussed in relation to the generation of reactive oxygen species, membrane disruption, extracellular polymeric substance degradation, biofilm eradication, and pathogen inactivation. Representative applications in food-contact surface decontamination, antimicrobial packaging, fresh produce preservation, and intelligent food processing are critically evaluated using recent experimental evidence. Beyond antimicrobial performance, this review introduces a safe-by-design framework that integrates material engineering with toxicological assessment, nanoparticle migration, environmental fate, regulatory considerations, and scalable manufacturing. Emerging opportunities for artificial intelligence-assisted nanozyme design, high-throughput materials discovery, and data-driven optimization are also discussed as transformative approaches for accelerating industrial translation. By integrating materials science, catalytic mechanisms, food microbiology, and safety assessment, this review establishes a comprehensive framework for the rational development of next-generation catalytic nanozymes toward sustainable, effective, and industrially applicable antimicrobial food systems. Full article

The rapid emergence of carbapenem-resistant Acinetobacter baumannii has become a major health concern, primarily driven by the dissemination of class D β-lactamases, particularly OXA-23, which compromise the efficacy of last-line β-lactam antibiotics. Drug repurposing combined with structure-based computational approaches provides a promising strategy for accelerating the discovery of novel therapeutic candidates against multidrug-resistant pathogens. This study aimed to identify FDA-approved non-steroidal anti-inflammatory drugs (NSAIDS) with potential inhibitory activity against OXA-23 β-lactamase by using a comprehensive computational drug discovery workflow. Twenty-six FDA-approved NSAIDs were evaluated using an integrated computational pipeline comprising network pharmacology, KEGG pathway analysis, molecular docking, molecular dynamics simulations and ADMET profiling. KEGG pathway analysis confirmed the central role of OXA-23 in β-lactam resistance, while network pharmacology prioritized nine candidates NSAIDS for subsequent structure-based investigation. Molecular docking was performed using the crystal structure of OXA-23 β-lactamase (PDB ID: 4K0X), followed by molecular dynamics simulations to assess the stability of the protein–ligand complexes. Among the prioritized compounds, sulfasalazine demonstrated the most favorable predicted binding affinity (−8.3 kcal/mol), forming stable interactions with key catalytic residues, including SER126, VAL128, and LEU166 and exhibiting a more favorable docking profile than the reference drug imipenem (−5.7 kcal/mol). Molecular dynamics simulations supported the structural stability of the sulfasalazine OXA-23 complex throughout the simulation period. Furthermore, ADMET analysis indicated favorable pharmacokinetic characteristics including good oral bioavailability, high gastrointestinal absorption, low central nervous system penetration, and an acceptable predicted safety profile. This integrated computational study identifies sulfasalazine as a promising repurposing candidate for targeting OXA-23 β-lactamase in carbapenem-resistant A. baumannii. The findings demonstrate the utility of combining network pharmacology with molecular modeling to prioritize candidate therapeutics and provide a computational framework for accelerating antimicrobial drug discovery. Experimental validation is warranted to confirm the inhibitory activity and therapeutic potential of sulfasalazine against multidrug-resistant A. baumannii. Full article

Nanoparticles have attracted considerable interest for biomedical and catalytic applications due to their unique functional properties. This study aims to evaluate the structural, optical, photoelectric, photocatalytic, and wound-healing performance of cetyltrimethylammonium bromide (CTAB) and cellulose nanoparticles with complementary physicochemical characteristics. The nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Ultraviolet–Visible (UV–Vis) spectroscopy, while photoelectric properties were assessed through current–voltage (I–V) measurements. Photocatalytic activity was evaluated using methylene blue degradation under solar irradiation, and in vivo wound healing was examined using a rat excisional model over 13 days. Cellulose nanoparticles exhibited nearly double the photocurrent compared to CTAB, indicating enhanced charge transport efficiency. Photocatalytic results showed that cellulose achieved approximately ~70% degradation within 210 s, compared to ~50% for CTAB. In vivo findings revealed that cellulose achieved 82% wound closure, compared with 71% for CTAB, 67% for Betadine, and 35% for untreated controls, accompanied by improved tissue regeneration. Overall, cellulose nanoparticles exhibited better photoelectrochemical, photocatalytic, and wound-healing properties, whereas CTAB provided structural integrity and antimicrobial properties. These materials are therefore promising multifunctional nanomaterials for catalytic and biological applications. Full article

This work presents a sustainable strategy for the fabrication of multifunctional silver nanoparticles (Ag-NPs) and Ag/jute nanocomposites using Erythroxylum coca tea waste extract as a bioreducing and stabilizing agent, combined with picosecond pulsed laser irradiation. UV–Vis spectroscopy and transmission electron microscopy revealed the formation of Ag-NPs with diverse morphologies and broad size distributions, which became significantly more uniform after laser post-treatment without the need for additional chemical reagents. Following laser irradiation, the initially broad Ag surface plasmon resonance (SPR) peak transformed into a symmetric Gaussian-shaped band, centered at 407 ± 3 nm for all the Ag-NPs systems. The catalytic performance of unsupported Ag-NPs and Ag-NPs supported on jute fibers was comparatively evaluated by degrading Congo red (CR) dye, revealing that the supported nanocomposites exhibited enhanced catalytic stability, higher pollutant removal efficiency, and improved catalyst recovery. Furthermore, multicomponent catalytic reduction experiments involving CR and 4-nitrophenol (4-NP) in the presence of NaBH₄ revealed simultaneous degradation and reduction pathways mediated by the Ag/jute nanocomposites, as evidenced by the emergence of new absorption bands during the reaction. In parallel, the synthesized Ag-NPs demonstrated pronounced antimicrobial activity against Escherichia coli, generating well-defined inhibition zones. Beyond conventional approaches centered on nanoparticle synthesis and morphology optimization, this study establishes a platform that combines agricultural waste valorization, laser-assisted nanoparticle engineering, and natural-fiber-supported nanocomposite fabrication, enabling efficient remediation of both single- and multicomponent pollutant systems while promoting catalyst reusability and environmental sustainability. These findings demonstrate the Ag/jute nanocomposites as sustainable and scalable catalytic materials for wastewater remediation and antimicrobial applications. Full article

Background: Bacterial adaptation to environmental and chemical stress involves coordinated, system-level responses collectively described as perturbome. Understanding conserved elements within core perturbomes may reveal strategic vulnerabilities for antimicrobial development. Methods: In this study, we implemented an integrative framework combining functional and comparative genomics, drug–target interactions and molecular docking to prioritize conserved stress-response targets in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Results: A total of 147 genes from previously defined core perturbomes were analyzed through interactome reconstruction and functional enrichment. Interactome and functional analyses revealed significant connectivity and functional clustering, primarily associated with molecule biosynthesis, translation, transcriptional regulation, and energy metabolism. Orthology-based comparative genomics identified six conserved orthogroups shared across at least two species, representing key stress-adaptive nodes including fatty acid synthesis initiation, metabolic stress buffering, transcription termination (Rho), ATP synthesis, peptidoglycan remodeling, and UDP-glucose-mediated envelope biosynthesis. Drug–target interaction analyses suggested that these conserved proteins are modulated by enzymatic inhibitors, metabolite analogs, or active-site competitors. Structural and docking analyses focused on a selected protein, FabF (β-ketoacyl-ACP synthase II) and confirmed catalytically coherent binding of cerulenin within the active site, with high concordance between experimentally resolved and AlphaFold-predicted structures, supporting the reliability of structure-based prioritization. Conclusions: Overall, the results demonstrate that bacterial stress responses converge on evolutionarily conserved metabolic and regulatory elements essential for homeostasis and tolerance to perturbations, being the first work integrating core perturbome data from different microorganisms. The proposed perturbome-informed framework provides a rational strategy to identify robust, broad-spectrum antimicrobial targets and highlights opportunities for drug repurposing and future experimental validation. Full article

Describing novel microbial species opens access to uncharted biosynthetic gene clusters and their associated secondary metabolites, offering fresh opportunities in the search for new antibiotics urgently needed to combat multidrug resistance. In this study, we describe a new species of Streptomyces, S. marxii sp. nov. (type strain VKM Ac-3100), an actinobacterium isolated from soil in the Yaroslavl Region of Russia. Using a polyphasic taxonomic approach that included whole-genome sequencing (WGS), we found that the strain’s average nucleotide identity (ANI) and digital DNA–DNA hybridisation (dDDH) values relative to its closest relative, S. maoxianensis, were 92.53% and 47.9%, respectively. Both values fell significantly below the species delimitation thresholds. Functional screening using the pDualrep2 dual fluorescent reporter system identified a unique SOS-silent antimicrobial profile characterised by growth inhibition without induction of the SOS response or translation stress. High-resolution mass spectrometry (HRMS) and genomic mining revealed that this activity is linked to the production of kinanthraquinone B ([M+H]⁺ m/z 275.0550), a rare polycyclic aromatic polyketide. Genomic analysis identified a specialised type II polyketide synthase (T2PKS) biosynthetic gene cluster (BGC) with evidence of acquisition via horizontal gene transfer (HGT). Our findings characterise S. marxii as a promising natural producer of rare catalytic inhibitors of DNA topoisomerases II and IV, offering a scaffold for the development of antibiotics with potentially lower genotoxicity. Full article

To address the emerging multidrug-resistance crisis caused by Klebsiella pneumoniae, we expressed the endolysin Lys59 derived from phage VB_KpP_HS106 and performed a comprehensive analysis of its antibacterial activity and structural features. Molecular modeling revealed that Lys59 carries a highly positively charged N-terminus and an amphipathic helix at the C-terminus. In vitro antibacterial assays showed that Lys59 exhibited significant bactericidal activity against K. pneumoniae with an approximately 4 log reduction at 50 µg/mL in 2 h. Meanwhile, Lys59 exhibited potent, broad-spectrum activity against both Gram-negative and Gram-positive bacteria. Stability analysis indicated that Lys59 retained high activity over a pH range of 3–9 and a temperature range of 4–55 °C. Notably, the antibacterial activity of Lys59 was found to be regulated by metal ions. Molecular docking indicated that K⁺ can enhance binding stability by interacting with ASN35 and VAL57. In contrast, Mg²⁺ and Ca²⁺ suppressed catalytic function by binding to the essential GLU17 residue. Furthermore, treatment with 200 µg/mL of Lys59 resulted in a 44.6% reduction in K. pneumoniae biofilm biomass. Overall, this study identified a phage-derived endolysin with broad-spectrum antimicrobial activity and demonstrated its potential as an antibacterial agent against multidrug-resistant K. pneumoniae. Full article