Antimicrobial Effects Research Articles

Cinnamaldehyde in Focus: Antimicrobial Properties, Biosynthetic Pathway, and Industrial Applications

Trans-cinnamaldehyde (TCA), a major bioactive compound derived from cinnamon (Cinnamomum spp.), has garnered significant attention for its diverse therapeutic properties. Its broad-spectrum antimicrobial activity, targeting both Gram-positive and Gram-negative bacteria as well as various fungi, positions TCA as a potent natural antimicrobial agent. Beyond its antimicrobial effects, TCA demonstrates promising antidiabetic and anti-inflammatory activities, making it a valuable compound in medicinal and cosmetic applications. Recent studies have highlighted its role in disrupting microbial membranes, inhibiting biofilm formation, and modulating key metabolic pathways in pathogens. Furthermore, TCA has gained popularity in cosmetics due to its antimicrobial activity, antioxidant properties, and skin-friendly profile. This review provides a comprehensive overview of TCA’s antimicrobial potential, focusing on its mechanisms of action and its market and industrial applications. We also discuss the biosynthetic pathway of TCA, exploring both its natural production in cinnamon and advances in biotechnological production methods. As the demand for sustainable and natural antimicrobial agents grows, TCA emerges as a promising candidate for diverse applications. Finally, this review explores future directions for optimizing TCA production through metabolic engineering and synthetic biology approaches to meet industrial-scale demands.

LysSYL-Loaded pH-Switchable Self-Assembling Peptide Hydrogels Promote Methicillin-Resistant Staphylococcus Aureus Elimination and Wound Healing.

Staphylococcus aureus (S. aureus), especially methicillin-resistant S. aureus (MRSA), causes wound infections, whose treatment remains a clinical challenge. Bacterium-infected wounds often create acidic niches with a pH 4.5-6.5. Endolysin LysSYL, which is derived from phage SYL, shows promise as an antistaphylococcal agent. However, endolysins generally exhibit instability and possess low bioavailability in acidic microenvironments. Here, an array of self-assembling peptides is designed, and peptide L5 is screened out based on its gel formation property and bioavailability. L5 exerted a pH-switchable antimicrobial effect (pH 5.5) and formed biocompatible hydrogels at neutral pH (pH 7.4). The LysSYL-loaded L5 can assemble L5@LysSYL hydrogels, increase thermal stability, and exhibit the slow-release effect of LysSYL. Effective elimination of S. aureus is achieved by L5@LysSYL through bacterial membrane disruption and cell separation inhibition. Moreover, L5@LysSYL hydrogels exhibit great potential in promoting wound healing in a mouse wound model infected by MRSA. Furthermore, L5@LysSYL hydrogels are safe and can decrease the cytokine levels and increase the number of key factors for vessel formation, which contribute to wound healing. Overall, the self-assembling L5@LysSYL can effectively clean MRSA and promote wound healing, which suggests its potential as a pH-sensitive wound dressing for the management of wound infections.

In Silico Study of the Potential Inhibitory Effects on Escherichia coli DNA Gyrase of Some Hypothetical Fluoroquinolone–Tetracycline Hybrids

Background/Objectives: Despite the discovery of antibiotics, bacterial infections persist globally, exacerbated by rising antimicrobial resistance that results in millions of cases, increased healthcare costs, and more extended hospital stays. The urgent need for new antibacterial drugs continues as resistance evolves. Fluoroquinolones and tetracyclines are versatile antibiotics that are effective against various bacterial infections. A hybrid antibiotic combines two or more molecules to enhance antimicrobial effectiveness and combat resistance better than monotherapy. Fluoroquinolones are ideal candidates for hybridization due to their potent bactericidal effects, ease of synthesis, and ability to form combinations with other molecules. Methods: This study explored the mechanisms of action for 40 hypothetical fluoroquinolone–tetracycline hybrids, all of which could be obtained using a simple, eco-friendly synthesis method. Their interaction with Escherichia coli DNA Gyrase and similarity to albicidin were evaluated using the FORECASTER platform. Results: Hybrids such as Do-Ba, Mi-Fi, and Te-Ba closely resembled albicidin in physicochemical properties and FITTED Scores, while Te-De surpassed it with a better score. Similar to fluoroquinolones, these hybrids likely inhibit DNA synthesis by binding to enzyme–DNA complexes. Conclusions: These hybrids could offer broad-spectrum activity and help mitigate bacterial resistance, though further in vitro and in vivo studies are needed to validate their potential.

Review: Advances in Self-Preservation Techniques in Cosmetics Using Hurdle Technology

Preservatives are essential in cosmetic products to prevent microbial growth, extending product shelf life and ensuring user safety by minimizing infection risks. While traditional chemical preservatives have long been effective in protecting against microbial contamination, growing consumer concerns over their safety and potential health impacts are prompting a shift toward preservative-free or self-preserving cosmetic formulations. This shift has increased interest in developing products that maintain antimicrobial effectiveness without synthetic preservatives, with hurdle technology emerging as a promising approach.Originally applied in the food industry in the 1970s, hurdle technology involves combining multiple preservation strategies to inhibit microbial growth without relying on traditional preservatives. In cosmetic applications, hurdle technology can reduce or eliminate the need for synthetic preservatives by implementing several protective measures. These “hurdles” may include high manufacturing standards, protective packaging, emulsions that limit microbial growth, controlled water activity, and pH adjustments to create an environment less conducive to microbial survival.This review explores the adaptation of hurdle technology principles in cosmetics, focusing on techniques for creating self-preserving formulations. It highlights the role of multifunctional ingredients with natural antimicrobial properties, such as plant-derived essential oils, which can serve as alternatives to chemical preservatives. These ingredients not only inhibit microbial growth but also provide additional benefits, aligning with consumers' growing preference for natural, safe, and effective skincare options.

In Vitro Antimicrobial Effectiveness of Calcium Hydroxide and Its Combination with Sodium Hypochlorite against Enterococcus Faecalis and Candida Albicans

The aim of this in vitro study was to evaluate and compare the antimicrobial effect of calcium hydroxide (〖Ca(OH)〗_2) and its combination with 5% sodium hypochlorite (NaOCL) as intracanal medicaments against Enterococcus faecalis (E. faecalis) and Candida albicans after one, three and seven days. Inoculate of these organisms (E. faecalis and candida albicans) were used to make lawn cultures on Mueller-Hinton with 5% defibrinated sheep blood agar and Mueller-Hinton agar. 60 wells with a depth of 4 mm were prepared for E. faecalis. Then 20 wells filled with 〖Ca(OH)〗_2, 20 wells filled with combination of 〖Ca(OH)〗_2 and 5% NaOCL, and last 20 wells were filled with distilled water as control. A similar procedure was conducted for Candida albicans. The zone of inhibition for each material used against a particular organism were measured and recorded after 1, 3, and 7 days. 〖Ca(OH)〗_2 in combination with 5% NaOCL is more effective than 〖Ca(OH)〗_2 alone against E. faecalis and Candida albicans at different time periods. E. faecalis was more resistant than Candida albicans to intracanal medicaments used. The antimicrobial effect depends on how long it remains inside the root canal. Mixing of 〖Ca(OH)〗_2 with 5% NaOCL had antimicrobial effect on both E. faecalis and Candida albicans and it was more effective against Candida albicans.

Antimicrobial neuropeptides and their therapeutic potential in vertebrate brain infectious disease

The defense mechanisms of the vertebrate brain against infections are at the forefront of immunological studies. Unlike other body parts, the brain not only fends off pathogenic infections but also minimizes the risk of self-damage from immune cell induced inflammation. Some neuropeptides produced by either nerve or immune cells share remarkable similarities with antimicrobial peptides (AMPs) in terms of size, structure, amino acid composition, amphiphilicity, and net cationic charge. These similarities extend to a wide range of antibacterial activities demonstrated in vitro, effectively protecting nerve tissue from microbial threats. This review systematically examines 12 neuropeptides, pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal peptide (VIP), α-melanocyte stimulating hormone (α-MSH), orexin-B (ORXB), ghrelin, substance P (SP), adrenomedullin (AM), calcitonin-gene related peptide (CGRP), urocortin-II (UCN II), neuropeptide Y (NPY), NDA-1, and catestatin (CST), identified for their antimicrobial properties, summarizing their structural features, antimicrobial effectiveness, and action mechanisms. Importantly, the majority of these antimicrobial neuropeptides (9 out of 12) also possess significant anti-inflammatory properties, potentially playing a key role in preserving immune tolerance in various disorders. However, the connection between this anti-inflammatory property and the brain’s infection defense strategy has rarely been explored. Our review suggests that the combined antimicrobial and anti-inflammatory actions of neuropeptides could be integral to the brain’s defense strategy against pathogens, marking an exciting direction for future research.

Design, Synthesis, ssDNA Binding Affinities, and Evaluation of Novel Metal‐Centered Ferrocene as an Effective Antimicrobial and DNA Cleavage Agent

ABSTRACTMetal (Co3+, Ni2+, and Pt2+)–centered and noncentered ferrocene–Schiff bases were prepared. They have been structurally characterized by spectroscopic methods, elemental analysis, conductivity, and magnetic moment. Electron spin resonance was used for the characterization of the Co3+‐centered complex. All synthesized compounds showed antibacterial activity against all tested Gram‐positive and Gram‐negative strains, as well as potent antifungal effect against Candida species. Remarkably, these compounds demonstrated greater efficacy against Gram‐positive bacteria than Gram‐negative. Without an additional oxidant or reductant, the compounds exhibited DNA cleavage capability in the dark. The development of synthesized novel chemical compounds having DNA cleavage and antimicrobial activity plays a profound role in the advancement of medical therapeutics.

Insights into the Acute Stress of Glutaraldehyde Disinfectant on Short-Term Wet Anaerobic Digestion System of Pig Manure: Dose Response, Performance Variation, and Microbial Community Structure

The outbreak of epidemics such as African swine fever has intensified the use of disinfectants in pig farms, resulting in an increasing residual concentration of disinfectants in environmental media; however, the high-frequency excessive use of disinfectants that damage pig farm manure anaerobic fermentation systems and their mechanisms has not attracted enough attention. Especially, the complex effects of residual disinfectants on anaerobic fermentation systems for pig manure remain poorly understood, thus impeding the application of disinfectants in practical anaerobic fermentation systems. Herein, we explored the effects of glutaraldehyde disinfectant on methane production, effluent physicochemical indices, and microbial communities in a fully automated methanogenic potential test system (AMPTSII). The results show that adding glutaraldehyde led to remarkable alterations in methane production, chemical oxygen demand (COD), volatile solids (VS), and polysaccharide and phosphorus concentrations. During the anaerobic process, the production of methane displayed a notable decrease of 5.0–98% in all glutaraldehyde treatments, and the trend was especially apparent for treatments containing high levels of glutaraldehyde. Comparisons of the effluent quality showed that in the presence of 0.002–0.04% glutaraldehyde, the COD and total phosphorus (TP) increased by 12–310% and 15–27%, respectively. Moreover, the addition of 0.01–0.08% glutaraldehyde decreased the ammonium (NH4+-N) concentration and VS degradation rate by 7.7–15% and 4.9–26.2%. Furthermore, microbiological analysis showed that the glutaraldehyde treatments had adverse effects on the microbial community. Notably, certain functional bacteria were restrained, as highlighted by the decreases in relative abundance and microbial diversity by 1.3–17% and 0.06–21%, respectively. This study provides a theoretical basis for the rational use of disinfectants in anaerobic fermentation systems.

The antimicrobial and antibiofilm effects of gentamicin, imipenem, and fucoidan combinations against dual-species biofilms of Staphylococcus aureus and Acinetobacter baumannii isolated from diabetic foot ulcers.

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia due to impaired insulin production or utilization, leading to severe health complications. Diabetic foot ulcers (DFUs) represent a major complication, often exacerbated by polymicrobial infections involving Staphylococcus aureus and Acinetobacter baumannii. These pathogens, notorious for their resistance to antibiotics, complicate treatment efforts, especially due to biofilm formation, which enhances bacterial survival and resistance. This study explores the synergistic effects of combining gentamicin, imipenem, and fucoidan, a sulfated polysaccharide with antimicrobial properties, against both planktonic and biofilm forms of S. aureus and A. baumannii. Isolates of S. aureus and A. baumannii were collected from DFUs and genetically confirmed. Methicillin resistance in S. aureus was identified through disk diffusion and PCR. Biofilm formation, including dual-species biofilms, was analyzed using the microtiter plate method. The antimicrobial efficacy of gentamicin, imipenem, and fucoidan was assessed by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC). Synergistic interactions were evaluated using the fractional inhibitory concentration index (FICi) and fractional bactericidal concentration index (FBCi). The expression of biofilm-associated genes (icaA in S. aureus and bap in A. baumannii) was analyzed, and the cytotoxicity of fucoidan was assessed. The study revealed that 77.4% of S. aureus and all A. baumannii isolates showed multidrug resistance. Among 837 tested conditions for dual-species biofilm formation, 72 resulted in strong biofilm formation and 67 in moderate biofilm formation. The geometric mean MIC values for gentamicin were 12.2µg/mL for S. aureus, 22.62µg/mL for A. baumannii, and 5.87µg/mL for their co-culture; for imipenem, they were 19.84, 9.18, and 3.70µg/mL, respectively, and for fucoidan, 48.50, 31.20, and 19.65µg/mL, respectively. The MBC values for gentamicin were 119.42, 128, and 11.75µg/mL; for imipenem, they were 48.50, 14.92, and 8µg/mL; and for fucoidan, they were 88.37, 62.62, and 42.48µg/mL. The MBIC values were 55.71, 119.42, and 18.66µg/mL for gentamicin; 68.59, 48.50, and 25.39µg/mL for imipenem; and 153.89, 101.49, and 53.53µg/mL for fucoidan. The MBEC values were 315.17, 362.03, and 59.25µg/mL for gentamicin; 207.93, 157.58, and 74.65µg/mL for imipenem; and 353.55, 189.46, and 99.19µg/mL for fucoidan. When cultured in planktonic form, the geometric mean FICi and FBCi values indicated additive effects, while co-culture showed FICi values of ≤ 0.5, suggesting a synergistic interaction. Treatment with gentamicin and fucoidan led to significant downregulation of the icaA and bap genes in both single-species and dual-species biofilms of S. aureus and A. baumannii. The reductions in gene expression were more pronounced in dual-species biofilms compared to single-species biofilms. Additionally, treatment with imipenem and fucoidan also resulted in significant downregulation of these genes in both biofilm types. Cytotoxicity assessments indicated that higher concentrations of fucoidan were toxic, yet no harmful effects were noted at the optimal synergistic concentrations used with antibiotics. In our investigation, we found that combining gentamicin, imipenem, and fucoidan had a synergistic effect on dual-species biofilms of S. aureus and A. baumannii, suggesting potential benefits for treating such infections effectively. This underscores the importance of understanding microbial interactions, antibiotic susceptibility, and biofilm formation in DFUs.

Perceptions of distinctions between patient and healthcare zones among intensive care unit nurses at a Korean tertiary hospital: A cross-sectional study.

Intensive care unit (ICU) patients face higher infection risks from invasive procedures, highlighting the critical role of ICU nurses in infection prevention. Clear differentiation between the patient and healthcare zones is essential for effective hand hygiene and disinfection, yet research on this topic is limited. To assess ICU nurses' perception of the concept of patient and healthcare zones and evaluate their similarity and accuracy in identifying the zones. A descriptive survey was conducted at a 2,732-bed tertiary hospital in Korea from 28 July to 27 August 2022. Participants were recruited from various ICUs through flyers. 225 questionnaires-with illustrations 27 item locations for three ICU scenarios-were made available at nursing stations for voluntary completion. Participants were asked to classify items into the patient zone or the healthcare zone. Similarity scores reflected participant agreement, while accuracy scores measured the proportion of correct answers. Participants' free-text opinions regarding zone classification were analysed thematically. 104 nurses participated voluntarily. Average similarity and accuracy were 84.7% and 82.7%, respectively. The top 8 items, with over 97% similarity and accuracy, were all frequently in contact with ICU patients (e.g., pulse oximeter, Levin tube, central line, urine bag, and patient bed). The bottom 7 items, with less than 80%, included the glucometer, flashlight, trolley, and sink. Participants with higher education levels had significantly higher similarity (p = .044) and accuracy (p = .033), whereas those already familiar with the patient-zone concept had significantly higher accuracy (p = .009). From the free-text analysis, participants considered factors beyond proximity to the patient, such as patient contact, room type, and distance. To address zone classification challenges, clear criteria for patient and healthcare zones, space redesign, and educational programs are recommended. Further research is necessary to improve greater clarity and consensus regarding patient and healthcare zones to enhance infection control practices.

Therapeutic deep eutectic solvent with saponin, optimized through response surface methodology, exert potent in vivo antimicrobial effects against Pseudomonas aeruginosa.

Therapeutic deep eutectic solvents (THEDES) are a type of deep eutectics that can be used as active pharmaceutical ingredients (APIs) by enhancing the drug bioavailability, by increasing the solubility of APIs in aqueous solutions or by increasing their permeability through biological barriers. In this study, we demonstrate the utility of designer THEDES, based on Quillaja Saponin (SAP), a triterpene natural product to unravel the antimicrobial potential of such THEDES. THEDES were prepared by gently mixing and heating five different α- hydroxy acids- malic, citric, tartaric, glycolic, lactic acids and SAP with water as a third component in the THEDES. The antimicrobial assays were performed with the as-prepared SAP-THEDES and among the panel of bacterial strains, saponin-malic acid THEDES [SMA-THEDES] displayed potent activity in disassembling PA biofilms, demonstrating that the SMA-THEDES can serve as therapeutic antibacterial biomaterials. To further optimize, a Box-Behnken- response surface methodology (RSM) experimental design was done and at the optimum conditions of SAP (1.014m.mol), Malic acid (1.003m.mol), Water (0.117m.mol), SMA-THEDES exhibited maximum MIC of P. aeruginosa with the minimum absorbance at 590nm of 0.105. The effectiveness of SMA-THEDES as antibiofilm agents on P. aeruginosa with the mechanism studies have been explored. The colony count from the in vivo infection zebrafish model in the treatment group showed a decline of > 2 fold for SMA-THEDES. Toxicity studies did not reveal any abnormality in liver and brain enzyme levels. Liver morphology images show no severe cytological alterations when treated with SMA-THEDES and were almost similar to the normal liver.

A Comparative Evaluation of the Antimicrobial Properties of 50% Grape Seed Extract, N-acetyl Cysteine and 5.25% Sodium Hypochlorite against Enterococcus faecalis (ATCC 19433) – An In vitro Study

Abstract Introduction: Endodontic infections are complex and polymicrobial, presenting significant challenges in dental treatment. Eliminating bacteria is the main objective of endodontic preparation, ensuring a tight seal to prevent reinfection. A commonly isolated bacterium, Enterococcus faecalis, is Gram positive and facultative anaerobic. It thrives in low-nutrient environments, forming resilient biofilms. Due to its tissue dissolving properties and broad-spectrum antimicrobial, sodium hypochlorite (NaOCl) is the most sought after irrigant, but its cytotoxicity is a concern. Alternatives such as grape seed extract (GSE) and N-acetyl cysteine (NAC) are being explored for their potential antimicrobial effects and biocompatibility. Materials and Methods: Forty single-rooted, non-carious premolars extracted for orthodontic reasons were selected. Teeth were cleaned, sectioned and prepared, ensuring apical patency. Specimens were autoclaved and contaminated with E. faecalis (ATCC 19433) for 30 days. Four groups (n = 10) were formed: Group I – GSE 50%, Group II – NAC 200 mg/ml, Group III – NaOCl 5.25% and Group IV – sodium chloride (0.9%). Manufacturer’s instructions were followed precisely to prep the solutions, and root canals were treated using the Reciproc R25 instrument. Samples were collected before (F1) and after (F2) instrumentation and irrigation. Colony-forming units (CFUs) were quantified and analysis was done using two-way analysis of variance and Tukey’s honestly significant difference post hoc tests, with significance set at P < 0.05. Results: NaOCl significantly reduced CFU counts, demonstrating superior antimicrobial efficacy compared to NAC and GSE (P < 0.01). In comparison to negative control and GSE (P < 0.01), NAC showed significant antimicrobial activity, but not significantly different from GSE (P > 0.05). GSE displayed potential antimicrobial properties but was less effective than NaOCl and NAC. Conclusion: NaOCl remains the most effective irrigant; however, NAC and GSE also demonstrated significant antimicrobial properties and could serve as adjuncts in endodontic therapy. Further research is needed to optimise their formulations and validate clinical applications.

Biofabrication and Characterisation of Ni‐Doped SnO2 Nanoparticles With Enhanced Cytotoxicity, Antioxidant, Antimicrobial and Photocatalytic Activities

ABSTRACTThe present work focuses on Annona muricata leaf extract–mediated green synthesis of pure and nickel‐doped tin oxide nanoparticles for 3%, 5% and 7% concentrations. The properties of the obtained nanoparticles were investigated through XRD, FTIR, XPS, HRTEM–SAED, SEM–EDX and UV–visible spectroscopy techniques. The XRD pattern reveals all samples have tetragonal structures with high crystallinity. The Sn–O stretching vibration has been confirmed through FTIR spectra. The XPS results demonstrate that Sn0.93Ni0.07O2 nanoparticles have Sn3d, Ni2p and O1s oxidation states. EDX spectra contain Ni, Sn and O elements, which indicate the purity of the samples. UV–visible absorption spectrum shows decreases in optical energy bandgap with increases in nickel dopant concentration. The samples exhibit notable antibacterial activity against P. aeruginosa and S. aureus. Also, Sn0.93Ni0.07O2 nanoparticle has higher antifungal activity against A. niger than against C. albicans. Moreover, SnO2 nanoparticles have considerable antioxidant activity in DPPH scavenging compared to Sn0.93Ni0.07O2 nanoparticles. Furthermore, SnO2 nanoparticles have a better cytotoxic effect for L929 normal fibroblast cell lines with an LD50 value of 146.42 μg/mL. Additionally, the photocatalytic activity of SnO2 and Sn0.93Ni0.07O2 nanoparticles was done against methylene blue dye under direct sunlight irradiation. Overall, environmentally friendly synthetic pure and Ni‐doped SnO2 nanoparticles can be used in wastewater filter technologies as well as in medical aids due to their better cytotoxic, antioxidant and antimicrobial effects.

The preliminary study of antifungal and antibacterial properties of wine by-products

Background: Nowadays, the search for novel alternative antimicrobials has gained significant popularity. This surge is driven by the vast array of adverse effects of synthetic antimicrobials on human health and the environment. Consequently, the study of new natural sources of comparably ecologically safe and simultaneously effective antimicrobials is extremely important. In this context, the interest in wine by-products is growing due to their diverse beneficial properties. Traditionally considered industrial waste, wine by-products now offer promising opportunities. Notably, the unique climatic and geographical features of Armenian black grape varieties, such as Areni sev, make their by-products an attractive subject for study, with potential applications in agriculture. Objective: The study aims to investigate the antifungal and antibacterial properties of wine by-products obtained from the Areni sev grape variety. Methods: For the extraction of bioactive compounds, frozen and dry samples were homogenized. The maceration was performed in 70% hydroethanolic solution after incubation on a magnetic stirrer at room temperature. The obtained extracts were filtered through a 0.45 µm filter and evaluated for antifungal and antibacterial activity by disco-diffusion method. Results: Hydroethanolic extracts of wine by-products have exhibited antifungal and antibacterial activities. Specifically, the frozen samples demonstrated low antifungal activity against the Penicillium canescens with a 7.5 mm growth inhibition zone. In contrast, dried samples showed no antifungal activity. The highest antifungal activity was observed against Aspergillus niger with growth inhibition zones of 18 mm (frozen samples) and 15 mm (dried samples), respectively. Regarding antibacterial activity, wine by-product hydroethanolic extracts showed extremely low efficacy. Notably, frozen samples exhibited an 8 mm growth inhibition zone against Curtobacterium flaccumfaciens and 6.35 mm against Xanthomonas vesicatoria. Extracts from dried samples demonstrated a 6.35 mm inhibition zone against Curtobacterium flaccumfaciens and a 7 mm growth inhibition zone against Xanthomonas vesicatoria. Conclusion: Summarizing the results of the conducted experiments, it can be concluded that the used wine by-product derived from Areni sev grape has demonstrated notable antimicrobial activities, with a stronger emphasis on antifungal properties. The extracts obtained from frozen samples exhibited greater efficacy than those derived from dried samples. Future research plans include a more detailed investigation of Areni sev grape wine by-products. Keywords: wine by-product, grape pomace, Areni sev, bioactive compounds, antimicrobial properties

Phytogenic Synthesis of Cuprous and Cupric Oxide Nanoparticles Using Black jack Leaf Extract: Antibacterial Effects and Their Computational Docking Insights

Background: Green synthesized nanoparticles (NPs) have gained increasing popularity in recent times due to their broad spectrum of antimicrobial properties. This study aimed to develop a phytofabrication approach for producing cuprous (Cu2O) and cupric oxide (CuO) NPs using a simple, non-hazardous process and to examine their antimicrobial properties. Methods: The synthesis employed Bidens pilosa plant extract as a natural reducing and stabilizing agent, alongside copper chloride dihydrate as the precursor. The biosynthesized NPs were characterized through various techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, ultraviolet–visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Results: XRD analysis confirmed that the synthesized CuO and Cu2O NPs exhibited a high degree of crystallinity, with crystal structures corresponding to monoclinic and face-centered cubic systems. SEM images revealed that the NPs displayed distinct spherical and sponge-like morphologies. EDS analysis further validated the purity of the synthesized CuO NPs. The antimicrobial activity of the CuO and Cu2O NPs was tested against various pathogenic bacterial strains, including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus, with the minimum inhibitory concentration (MIC) used to gauge their effectiveness. Conclusions: The results showed that the phytosynthesized NPs had promising antibacterial properties, particularly the Cu2O NPs, which, with a larger crystal size of 68.19 nm, demonstrated significant inhibitory effects across all tested bacterial species. These findings suggest the potential of CuO and Cu2O NPs as effective antimicrobial agents produced via green synthesis.

Salmonella Infantis Adhesion to Various Surfaces and In Vitro Antimicrobial Efficacy of Commercial Disinfectants

Salmonella Infantis poses a significant challenge in poultry production due to its persistence and resistance to disinfectants. This study investigated the survival of the S. Infantis strain on different surfaces and evaluated the efficacy of disinfectants in both preventing and treating biofilms. The survival of the tested S. Infantis strain was assessed on plastic and stainless steel surfaces after 24 and 48 h. The minimum inhibitory concentrations (MICs) of five disinfectants were determined, and their antiadhesion effectiveness was evaluated using crystal violet. The efficacy of biofilm treatment was evaluated by cell culturability. The results showed that the adhesion of S. Infantis was significantly higher on the plastic surface. The disinfectants were effective at reducing biofilm formation only within the first 24 h. Fresh solutions of disinfectants based on quaternary ammonium compounds exhibited the highest antimicrobial efficacy, while chlorocresol was the most effective for both the prevention and treatment of biofilms. The study results suggest that the presence of plastic surfaces may contribute to the dissemination of Salmonella. Additionally, the effectiveness of disinfectants varied based on storage conditions and contact time, while biofilms demonstrated reduced susceptibility compared to planktonic cells. However, given the laboratory scale of this study, further validation on a commercial scale is necessary to confirm these findings.

From Waste to Worth: Using Fermented Orange Pomace in Sustainable Feed Production

Modern agriculture faces the dual challenge of producing environmentally friendly feed while minimizing chemical fertilizers and energy use. This study evaluates the use of orange pomace fermentation liquor (OPFL) as a bio-fertilizer to enhance the growth and nutritional content of sprouted barley for sustainable feed production. We conducted multiple assays to determine OPFL’s growth-promotion potential, including in vitro phosphate solubilization, indole-3-acetic acid (IAA) production, biofilm formation, and antimicrobial effects. Biosafety assays confirmed the absence of coliforms and hemolytic activity. Four barley varieties (Giza 2000, Giza 138, Giza 132, and Giza 126) were treated with OPFL in a hydroponic germination system, with significant improvements observed across several parameters. For example, in Giza 2000, chlorophyll content increased from 4.28 to 4.74, protein content rose from 12.15% to 22.07%, and plant height grew from 13.6 cm to 16.4 cm, representing increases of 10.7%, 81.6%, and 20.6%, respectively. Fresh biomass yield also saw a slight increase, though not statistically significant. This comprehensive evaluation suggests that OPFL is a sustainable alternative to chemical fertilizers, enhancing barley yield and quality in animal feed systems.

Investigating the Antibacterial, Antioxidant, and Cholesterol-lowering Properties of Yogurt Fortified with Postbiotic of Lactobacillus acidophilus and Lactiplantibacillus plantarum in the Wistar Rat Model.

Postbiotics have gained attention in the food industry due to their functional properties and ease of use compared to their live parent cells. Postbiotics are the metabolic byproducts of probiotic microorganisms, offering advantages such as antimicrobial and anti-diabetic effects. The study aimed to explore the potential antibacterial, antioxidant, and cholesterol-lowering effects of postbiotics from Lactobacillus acidophilus (LA) and Lactiplantibacillus plantarum (LbP) through in vitro and in vivo studies. Freeze-dried postbiotics from L. acidophilus BLAC 258 and L. plantarum were used in yogurt to inhibit foodborne pathogens over a 21-day storage period at 4 °C. The cholesterol-lowering effects of the postbiotic yogurt were assessed in Wistar rats fed with Normal Basal Diet (NBD) and High Cholesterol Diet (HCD). All experiments were performed in triplicate, and the collected data were analyzed with a one-way ANOVA using SPSS v.20 (2021) software. The Tukey Honestly Significant Difference (HSD) test was used for means differences at the 95% confidence interval. The results showed that postbiotic-fortified yogurt exhibited significant antioxidant and antibacterial effects. The antioxidant capacity of the yogurt increasingly peaked at 48.81% on day 14. Also, Listeria monocytogenes counts in the postbiotic yogurt decreased by approximately 2 Log10 on day 3. High-cholesterol-fed rats receiving postbiotic yogurt experienced significant reductions in total cholesterol, triglycerides, and LDL levels. Overall results indicate that postbiotics functional yogurt might be a safe and effective strategy for managing cholesterol levels and inhibiting foodborne pathogens.

“Antimicrobial and antioxidant capacity of Dunaliella salina, Tetraselmis chuii and Isochrysis galbana and their potential use in food.” a systematic review

AbstractThe main compounds extracted from the biomass of marine microalgae have antioxidant, antimicrobial, antifungal, anti-inflammatory and antitumor effects, making the possibility of using these properties in the development of foods feasible. Despite the proven biological activity of microalgae, there are still challenges regarding the production and use of microalgal biomass or its derivatives in food industries that are related to high production costs, and there is little research regarding the evaluation of their safety and the search for their application in food development. Therefore, this research aimed to collect information regarding the biological activities of marine microalgae, which allows their use as a natural antimicrobial additive in food matrices and as an ingredient in the development of functional foods with antioxidant capacity. The search interval for the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines was five years. Different methods for the extraction of antioxidant and antimicrobial compounds from the marine microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbana were compared and discussed, and the viability of their use and application in food matrices and in the food industry in general were analyzed. It was concluded that there are research gaps in the use of microalgae biomass as an extract, the identification of bioactive molecules for use in the food industry as antimicrobial agents and for the development of functional foods with antioxidant capacity.

Biofilm Inhibition Activity of Fennel Honey, Fennel Essential Oil and Their Combination

The eradication of bacterial biofilms remains a persistent challenge in medicine, particularly because an increasing number of biofilms exhibit resistance to conventional antibiotics. This underscores the importance of searching for novel compounds that present antibacterial and biofilm inhibition activity. Various types of honey and essential oil were proven to be effective against a number of biofilm-forming bacterial strains. The current study demonstrated the effectiveness of the relatively unexplored fennel honey (FH), fennel essential oil (FEO), and their combination against biofilm-forming bacterial strains Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and Escherichia coli, with a series of in vitro experiments. The authenticity of FH and FEO was checked with light microscopy and gas chromatography-mass spectrometry, respectively. Minimum inhibitory concentrations were determined using the microdilution method, and antibiofilm activity was assessed with crystal violet assay. Structural changes in bacterial cells and biofilms, induced by the treatments, were monitored with scanning electron microscopy. FEO and FH inhibited the biofilm formation of each bacterial strain, with FEO being more effective compared to FH. Their combination was the most effective, with inhibitory rates ranging between 87 and 92%, depending on the bacterial strain. The most sensitive bacterium was E. coli, while P. aeruginosa was the most resistant. These results provide justification for the combined use of honey and essential oil to suppress bacterial biofilms and can serve as a starting point to develop an effective surface disinfectant with natural ingredients.