Green synthesis of cellulose nanocrystal/ZnO bio-nanocomposites exerting antibacterial activity and downregulating virulence toxigenic genes of food-poisoning bacteria

Modulatory Effect of Competitive Exclusion on the Transmission of ESBL E. coli in Chickens

The extensive use of antimicrobial agents in broiler farms causes the emergence of antimicrobial resistance of E. coli producing severe economic losses to the poultry industry; therefore, monitoring the transmission of ESBL E. coli is of great significance throughout broiler farms. For this reason, we investigated the efficiency of competitive exclusion (CE) products to control the excretion and transmission of ESBL-producing E. coli in broiler chickens. Three hundred samples from 100 broiler chickens were screened for the incidence of E. coli by standard microbiological techniques. The overall isolation percentage was 39% and differentiated serologically into ten different serotypes: O158, O128, O125, O124, O91, O78, O55, O44, O2, and O1. The isolates represented absolute resistance to ampicillin, cefotaxime, and cephalexin. The effectiveness of CE (commercial probiotic product; Gro2MAX) on ESBL-producing E. coli (O78) isolate transmission and excretion was studied in vivo. The results showed that the CE product has interesting properties, making it an excellent candidate for targeted drug delivery by inhibiting bacterial growth and downregulating biofilm, adhesins, and toxin-associated genes loci. The histopathological findings demonstrated the capability of CE in repairing internal organ tissues. Our outcomes suggested that the administration of CE (probiotic products) in broiler farms could be a safe and alternative approach to control the transmission of ESBL-producing virulent E. coli in broiler chickens.

Enhancement of Visible Light Antibacterial Activities of Cellulose Fibers from Lotus Petiole Decorated ZnO Nanoparticles

Cellulose/ZnO (CZ) nanocomposites are promising antimicrobial materials known for their antibiotic-free nature, biocompatibility, and environmental friendliness. In this study, cellulose fibers extracted from lotus petioles were utilized as a substrate and decorated with various shapes of ZnO nanoparticles (NPs), including small bean, hexagonal ingot-like, long cylindrical, and hexagonal cylinder-shaped NPs. Increasing zinc salt molar concentration resulted in highly crystalline ZnO NPs forming and enhanced interactions between ZnO NPs and -OH groups of cellulose. The thermal stability and UV-visible absorption properties of the CZ samples were influenced by ZnO concentration. Notably, at a ZnO molar ratio of 0.1, the CZ 0.1 sample demonstrated the lowest weight loss, while the optical band gap gradually decreased from 3.0 to 2.45 eV from the CZ 0.01 to CZ 1.0 samples. The CZ nanocomposites exhibited remarkable antibacterial activity against both Staphylococcus aureus (S. aureus, Gram-positive) and Escherichia coli (E. coli, Gram-negative) bacteria under visible light conditions, with a minimum inhibitory concentration (MIC) of 0.005 mg/mL for both bacterial strains. The bactericidal effects increased with higher concentrations of ZnO NPs, even achieving 100% inhibition. Incorporating ZnO NPs onto cellulose fibers derived from lotus plants presents a promising avenue for developing environmentally friendly materials with broad applications in antibacterial and environmental fields.

Coated composite paper with nano-chitosan/cinnamon essential oil-nanoemulsion containing grafted CNC@ZnO nanohybrid; synthesis, characterization and inhibitory activity on Escherichia coli biofilm developed on grey zucchini

This investigation aims to highlight the applicability of a potent eco-friendly developed composite film to combat the Escherichia coli biofilm formed in a model food system. ZnO nanoparticles (NPs) synthesized using green methods were anchored on the surface of cellulose nanocrystals (CNCs). Subsequently, nano-chitosan (NCh) solutions were used to disperse the synthesized nanoparticles and cinnamon essential oil (CEO). These solutions, containing various concentrations of CNC@ZnO NPs and CEO, were sequentially coated onto cellulosic papers to inhibit Escherichia coli biofilms on grey zucchini slices. Six films were developed, and Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, biodegradation, and mechanical properties were assessed. The film containing 5 % nano-emulsified CEO + 3 % dispersed CNC@ZnO nano-hybrid in an NCh solution was selected for further testing since it exhibited the largest zone of inhibition (34.32 mm) against E. coli and the highest anti-biofilm activity on biofilms developed on glass surfaces. The efficacy of the film against biofilms on zucchini surfaces was temperature-dependent. During 60 h, the selected film resulted in log reductions of approximately 4.5 logs, 2.85 logs, and 1.57 logs at 10 °C, 25 °C, and 37 °C, respectively. Applying the selected film onto zucchini surfaces containing biofilm structures leads to the disappearance of the distinctive three-dimensional biofilm framework. This innovative anti-biofilm film offers considerable potential in combatting biofilm issues on food surfaces. The film also preserved the sensory quality of zucchini evaluated for up to 60 days.

Synthesis and characterization of bio-nanocomposite based on chitosan and CaCO3 nanoparticles for heavy metals removal

Water is a vital component of life; therefore, it is critical to have access to pure water for various life-sustaining activities including agriculture and human consumption. An eco-friendly nanocomposite based on chitosan (Cs) and nanomaterials (CaCO3-NPs) were combined to amalgamate the advantages of biopolymers and nanomaterials to overcome the problems of instability, poor mechanical properties, and low removal percentage of biopolymers. The as-prepared samples were characterized and were used for the removal of heavy metal from wastewater. X-ray diffractometer, Fourier transform infrared spectroscopy, and transmission electron microscope were used to distinguish the prepared absorbents. The absorption of the heavy metals by as-prepared samples was examined at different conditions. The kinetic and isotherm models of the adsorption process were also studied. The data showed that the removal percentages of Cd, Cu, Pb, Zn, Cr and Ni by the composite were 98.0, 94.8, 99.0, 97.9, 97.4 and 98.3 %, respectively. The kinetic and isothermal studies showed that the absorption of these metal ions by the samples obeyed a pseudo-second-order mechanism and Langmuir isotherm model, respectively. In addition, the maximum adsorption capacities of Cd, Cu, Pb, Zn, Cr, and Ni ions by as-prepared nanocomposite were 83.33, 47.84, 98.03, 89.28, 62.11, and 63.69 mg/g, respectively.

Cellulose-Based Metallogels-Part 3: Multifunctional Materials

The incorporation of the metal phase into cellulose hydrogels, resulting in the formation of metallogels, greatly expands their application potential by introducing new functionalities and improving their performance in various fields. The unique antiviral, antibacterial, antifungal, and anticancer properties of metal and metal oxide nanoparticles (Ag, Au, Cu, CuxOy, ZnO, Al2O3, TiO2, etc.), coupled with the biocompatibility of cellulose, allow the development of composite hydrogels with multifunctional therapeutic potential. These materials can serve as efficient carriers for controlled drug delivery, targeting specific cells or pathogens, as well as for the design of artificial tissues or wound and burn dressings. Cellulose-based metallogels can be used in the food packaging industry to provide biodegradable and biocidal materials to extend the shelf life of the goods. Metal and bimetallic nanoparticles (Au, Cu, Ni, AuAg, and AuPt) can catalyze chemical reactions, enabling composite cellulose hydrogels to be used as efficient catalysts in organic synthesis. In addition, metal-loaded hydrogels (with ZnO, TiO2, Ag, and Fe3O4 nanoparticles) can exhibit enhanced adsorption capacities for pollutants, such as dyes, heavy metal ions, and pharmaceuticals, making them valuable materials for water purification and environmental remediation. Magnetic properties imparted to metallogels by iron oxides (Fe2O3 and Fe3O4) simplify the wastewater treatment process, making it more cost-effective and environmentally friendly. The conductivity of metallogels due to Ag, TiO2, ZnO, and Al2O3 is useful for the design of various sensors. The integration of metal nanoparticles also allows the development of responsive materials, where changes in metal properties can be exploited for stimuli-responsive applications, such as controlled release systems. Overall, the introduction of metal phases augments the functionality of cellulose hydrogels, expanding their versatility for diverse applications across a broad spectrum of industries not envisaged during the initial research stages.

Evaluation of gene expression related to immunity, apoptosis, and gut integrity that underlies Artemisia's therapeutic effects in necrotic enteritis-challenged broilers

The experiment was designed to validate the effect of Artemisia annua and its novel commercial product (Navy Cox) on the control of necrotic enteritis (NE). A total of one hundred forty broiler chicks were randomly distributed into seven equal groups: G1, control negative; G2, infected with Eimeria (day 15) and C. perfringens (day 19); G3, treated with Navy Cox before challenge; G4, treated with Artemisia before challenge; G5, infected and then treated with Navy Cox; G6, infected and then treated with Artemisia; and G7, infected and treated with amoxicillin. Chicken response and immune organ indicants were recorded during the observation period (4 weeks). Whole blood and serum samples were collected for immunological evaluation, and tissue samples were collected for bacterial counts and estimation of mRNA expression of genes encoding apoptosis, tight junctions, and immunity. Chickens in the infected group revealed a significant decrease in RBCS, HB, PCV% total protein, Lysozyme, and nitric oxide activity in addition to leukocytosis, heterophilia, monocytosis, increase in cortisol, interleukins, and malondialdehyde. Treated groups displayed lower lesions, colony-forming units, and no mortality. Concurrently, a complete blood profile, antioxidants, and immune markers showed significant improvements. The mRNA expression levels of CASP, CLDN-1, OCLN, TJPI, MUC2, and cell-mediated immune response genes (p < 0.0001) were significantly alleviated in the treated groups compared with the challenged counterpart. This is the first-ever report on the efficacy valuation of Navy Cox compared to standard antibiotic treatment of clostridial NE. Navy Cox proved remarkable capability to minimize C. perfringens colonization in broiler intestines, modulation of mucus production, gut health integrity, immune organs, and immune response when used as a prophylactic agent in this form or naturally as Artemisia.

Multifunction smart nanocomposite film for food packaging based on carboxymethyl cellulose/Kombucha SCOBY/pomegranate anthocyanin pigment

Active packing systems employed to preserve food quality have gone through chains of sustainable development processes, reflecting the growth in consumer awareness of high-quality foods in eco-friendly packaging. Consequently, this study aims to develop antioxidant, antimicrobial, UV-shielding, pH-sensitive, edible, and flexible films from composites of carboxymethyl cellulose (CMC), pomegranate anthocyanin extract (PAE), and various fractions (1-15 %) of bacterial cellulose from the Kombucha SCOBY (BC Kombucha). Various analytical tools such as ATR-FTIR, XRD, TGA, and TEM were utilized to investigate the physicochemical characterization of BC Kombucha and CMC-PAE/BC Kombucha films. The DDPH scavenging test demonstrated the efficiency of PAE as a matrix with potent antioxidant properties, both as a solution and enclosed in composite films. The fabricated films of CMC-PAE/BC Kombucha showed antimicrobial activities against many pathogenic Gram-negative (Pseudomonas aeruginosa, Salmonella sp., and Escherichia coli), Gram-positive (Listeria monocytogenes and Staphylococcus aureus) bacteria, and Candida albicans, ranging from a 20 to 30 mm inhibition zone. The CMC-PAE/BC Kombucha nanocomposite has additionally been utilized to pack red grapes and plums. The results illustrated that CMC-PAE/BC Kombucha nanocomposite can increase red grapes and plums' shelf lives by up to 25 days while maintaining the fruits' quality better than those left unpacked.

Immobilization of TiO2NP@ oxidized cellulose nanocrystals for paper-based active packaging materials

In the current work, we present a renewable alternative coating formulation made of durable titania nanoparticles and oxidized nanocellulose (TiO₂NPs@OCNs) nanocomposites and sodium alginate (SA), to create an environmentally friendly and secure food packaging paper. OCNs sugarcane fibers are firstly hydrolyzed using ammonium persulphate (APS). Then, TiO₂NPs@OCNs nanocomposites are made in situ with OCNs using a green water-based sol-gel synthesis. Gram (+) microorganisms as well as Gram (-) bacteria are used to test the antibacterial properties of the TiO₂NPs@OCN dispersions. The results show that the TiO₂NP@OCNs significantly decreases the growth for all bacterial species. The TiO₂NP@OCNs nanocomposites are mixed with SA, and the resulting formulations are used to coat paper sheets. The corresponding physicochemical properties are evaluated using FTIR, TGA, AFM, SEM, and EDX. Furthermore, the mechanical strength, air permeability, and water vapor characteristics of the paper sheets treated with SA/TiO₂NPs@OCN are carried out, resulting in a great improvement of these properties. Finally, the SA/TiO₂NPs@OCNs coated papers have been used as packaging for strawberries. The findings demonstrate that coated papers could preserve strawberry quality better than unpacked fruit and extend strawberry shelf life from 6 to 18 days.

Nanotechnological approaches for management of soil-borne plant pathogens

Soil borne pathogens are significant contributor of plant yield loss globally. The constraints in early diagnosis, wide host range, longer persistence in soil makes their management cumbersome and difficult. Therefore, it is crucial to devise innovative and effective management strategy to combat the losses caused by soil borne diseases. The use of chemical pesticides is the mainstay of current plant disease management practices that potentially cause ecological imbalance. Nanotechnology presents a suitable alternative to overcome the challenges associated with diagnosis and management of soil-borne plant pathogens. This review explores the use of nanotechnology for the management of soil-borne diseases using a variety of strategies, such as nanoparticles acting as a protectant, as carriers of actives like pesticides, fertilizers, antimicrobials, and microbes or by promoting plant growth and development. Nanotechnology can also be used for precise and accurate detection of soil-borne pathogens for devising efficient management strategy. The unique physico-chemical properties of nanoparticles allow greater penetration and interaction with biological membrane thereby increasing its efficacy and releasability. However, the nanoscience specifically agricultural nanotechnology is still in its toddler stage and to realize its full potential, extensive field trials, utilization of pest crop host system and toxicological studies are essential to tackle the fundamental queries associated with development of commercial nano-formulations.

Boosting brackish water treatment via integration of mesoporous γ-Al2O3NPs with thin-film nanofiltration membranes

In this study, a simple method based on non-ionic surfactant polysorbates-80 was used to create mesoporous γ-Al₂O₃NPs. The properties of the prepared mesoporous alumina nanoparticles (Al₂O₃NPs) were verified using ATR-FTIR, XRD, SEM, TEM, DLS, and BET surface area analysis. Then, thin-film nanocomposite (TFN) nanofiltration membranes were fabricated by interfacial polymerization of embedded polyamide layers with varied contents (0.01 to 0.15 wt.%) of mesoporous γ-Al₂O₃NPs. The surface roughness, porosity, pore size, and contact angle parameters of all the prepared membranes were also determined. The performance of the fabricated membranes was investigated under various mesoporous γ-Al₂O₃NPs loads, time, and pressure conditions. Mesoporous γ-Al₂O₃NPs revealed an important role in raising both the membrane hydrophilicity and the surface negativity. The addition of 0.03 wt.% mesoporous γ-Al₂O₃NPs to the TFN membrane increased water flux threefold compared to the TF control (TFC) membrane, with maximum water flux reaching 96.5, 98, 60, and 52 L/(m².h) for MgSO₄, MgCl₂, Na₂SO₄, and NaCl influent solutions, respectively, with the highest salt rejection of 96.5%, 92.2%, 98.4%. The TFN-Al₂O₃ membrane was also able to soften water and remove polyvalent cations such as Mg²⁺ with a highly permeable flux. The TFN-Al₂O₃ membrane successfully removed the hardness of the applied water samples below the WHO limit compared to using merely the TFC membrane. Furthermore, the TFN-Al₂O₃ nanofiltration membrane unit proved to be a promising candidate for the desalination of real brine like that collected from the Safaga area, Egypt.