Combined antimicrobial effect of bacteriocins with other hurdles of physicochemic and microbiome to prolong shelf life of food: A review

Natural approach of using nisin and its nanoform as food bio-preservatives against methicillin resistant Staphylococcus aureus and E.coli O157:H7 in yoghurt

BACKGROUND

Natural antimicrobial agents such as nisin were used to control the growth of foodborne pathogens in dairy products. The current study aimed to examine the inhibitory effect of pure nisin and nisin nanoparticles (nisin NPs) against methicillin resistant Staphylococcus aureus (MRSA) and E.coli O157:H7 during the manufacturing and storage of yoghurt. Nisin NPs were prepared using new, natural, and safe nano-precipitation method by acetic acid. The prepared NPs were characterized using zeta-sizer and transmission electron microscopy (TEM). In addition, the cytotoxicity of nisin NPs on vero cells was assessed using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The minimum inhibitory concentrations (MICs) of nisin and its nanoparticles were determined using agar well-diffusion method. Further, fresh buffalo's milk was inoculated with MRSA or E.coli O157:H7 (1 × 106 CFU/ml) with the addition of either nisin or nisin NPs, and then the inoculated milk was used for yoghurt making. The organoleptic properties, pH and bacterial load of the obtained yoghurt were evaluated during storage in comparison to control group.

RESULTS

The obtained results showed a strong antibacterial activity of nisin NPs (0.125 mg/mL) against MRSA and E.coli O157:H7 in comparison with control and pure nisin groups. Notably, complete eradication of MRSA and E.coli O157:H7 was observed in yoghurt formulated with nisin NPs after 24 h and 5th day of storage, respectively. The shelf life of yoghurt inoculated with nisin nanoparticles was extended than those manufactured without addition of such nanoparticles.

CONCLUSIONS

Overall, the present study indicated that the addition of nisin NPs during processing of yoghurt could be a useful tool for food preservation against MRSA and E.coli O157:H7 in dairy industry.

Combined analysis of transcriptomics and metabolomics provide insights into the antibacterial mechanism of bacteriocin XJS01 against multidrug-resistant Staphylococcus aureus

Multidrug-resistant (MDR) bacteria are widespread in the environment and pose a serious threat to public health. It has been shown that bacteriocins have a great potential in controlling MDR pathogens, including Staphylococcus aureus. A previously reported Lactobacillus salivarius bacteriocin XJS01 exhibited good antibacterial activity against MDR S. aureus 2612:1606BL1486 (henceforth referred to as S. aureus_26), but its molecular mechanism remains unknown. Herein, we investigated the antibacterial mechanism of XJS01 on S. aureus_26 using an approach combining transcriptomics and metabolomics. The results showed that XJS01 induced significant changes at both transcriptional and metabolic levels in S. aureus_26. In total, 231 differentially expressed genes (DEGs) and 206 differentially abundance metabolites (DAMs) were identified in S. aureus_26 treated with 1 × MIC (minimum inhibition concentration) XJS01 compared with untreated (XJS01-free) cells (control). Functional analysis revealed that these DEGs and DAMs, alone with the related pathways and biological processes, were typically involved in stress response, being primarily related to metal uptake, cell virulence, self-help mechanism, amino acid and energy metabolism, bacterial stress response (e.g., two-component system), and membrane transport (e.g., phosphotransferase system). Overall, this study uncovered the multi-target effects of bacteriocins against MDR S. aureus at the genome-wide transcriptional and metabolic levels. These findings might be useful in the development of bacteriocins for the control of MDR S. aureus and other drug-resistant bacteria.

Comprehensive Review on the Biocontrol of Listeria monocytogenes in Food Products

Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a group of human illnesses that appear more frequently in countries with better-developed food supply systems. This review discusses the efficacy of actual biocontrol methods combined with the main types of food involved in illnesses. Comments on bacteriophages, lactic acid bacteria, bacteriocins, essential oils, and endolysins and derivatives, as main biological antilisterial agents, are made bearing in mind that, using them, food processors can intervene to protect consumers. Both commercially available antilisterial products and solutions presented in scientific papers for mitigating the risk of contamination are emphasized. Potential combinations between different types of antilisterial agents are highlighted for their synergic effects (bacteriocins and essential oils, phages and bacteriocins, lactic acid bacteria with natural or synthetic preservatives, etc.). The possibility to use various antilisterial biological agents in active packaging is also presented to reveal the diversity of means that food processors may adopt to assure the safety of their products. Integrating biocontrol solutions into food processing practices can proactively prevent outbreaks and reduce the occurrences of L. monocytogenes-related illnesses.

Improving quality of poultry and its meat products with probiotics, prebiotics, and phytoextracts

Remarkable changes have occurred in poultry farming and meat processing in recent years, driven by advancements in breeding technology, feed processing technology, farming conditions, and management practices. The incorporation of probiotics, prebiotics, and phytoextracts has made significant contributions to the development of poultry meat products that promote both health and functionality throughout the growth phase and during meat processing. Poultry fed with these substances improve meat quality, while incorporating probiotics, prebiotics, and phytoextracts in poultry processing, as additives or supplements, inhibits pathogens and offers health benefits to consumers. However, it is vital to assess the safety of functional fermented meat products containing these compounds and their potential effects on consumer health. Currently, there's still uncertainty in these aspects. Additionally, research on utilizing next-generation probiotic strains and synergistic combinations of probiotics and prebiotics in poultry meat products is in its early stages. Therefore, further investigation is required to gain a comprehensive understanding of the beneficial effects and safety considerations of these substances in poultry meat products in the future. This review offered a comprehensive overview of the applications of probiotics and prebiotics in poultry farming, focusing on their effects on nutrient utilization, growth efficiency, and gut health. Furthermore, potential of probiotics, prebiotics, and phytoextracts in enhancing poultry meat production was explored for improved health benefits and functionality, and possible issues associated with the use of these substances were discussed. Moreover, the conclusions drawn from this review and potential future perspectives in this field are presented.

Effect of sodium diacetate on fermentation, aerobic stability, and microbial diversity of alfalfa silage

Alfalfa (Medicago sativa L.) is a vital source of forage protein for ruminants, yet its ensiling poses challenges due to high buffering capacity and low water-soluble carbohydrates (WSC). This study investigated the impact of sodium diacetate (SDA) on alfalfa silage quality and aerobic stability. SDA was applied at four different rates to wilted alfalfa on a fresh basis: 0 g/kg, 3 g/kg, 5 g/kg, and 7 g/kg, and silages were ensiled in laboratory-scale silos for 45 days, followed by 7 days of aerobic exposure. A 16S rRNA gene sequencing assay using GenomeLab™ GeXP was performed to determine the relationship between dominant isolated lactic acid bacteria species and fermentation characteristics and aerobic stability on silage. The results showed that Lentilolactobacillus brevis, Pediococcus pentosaceus and Enterococcus faecium were the most prevalent bacteria when silos were opened, whereas Weissella paramesenteroides, Bacillus cereus, B. megaterium and Bacillus spp. were most prevalent bacteria after 7 days of aerobic exposure. Dry matter, pH, and WSC content were not affected by SDA, but doses above 5 g/kg induced a homofermentative process, which increased lactic acid concentration and lactic acid to acetic acid ratio, decreased yeast count during aerobic exposure, and improved aerobic stability. These findings offer useful information for optimizing SDA usage in silage, assuring improved quality and longer storage, and thereby improving animal husbandry and sustainable feed practices.

Ribosomally synthesized bacteriocins of lactic acid bacteria: Simplicity yet having wide potentials - A review

Bacteriocins are ribosomally made bacterial peptides that have outstanding contributions in the field of food industry, as biopreservatives, and promising potentials in the medical field for improving human and animal health. Bacteriocins have many advantages over antibiotics such as being primary metabolites with relatively simpler biosynthetic mechanisms, which made their bioengineering for activity or specificity improving purposes much easier. Also, bacteriocins are degraded by proteolytic enzymes and do not stay in environment, which reduce chances of developing resistance. Bacteriocins can improve activity of some antibiotics, and some bacteriocins show potency against multidrug-resistant bacteria. Moreover, some potent bacteriocins have antiviral, antifungal, and antiprotozoal (antileishmanial) activities. On the other hand, bacteriocins have been introduced into the treatment of some ulcers and types of cancer. These potentials make bacteriocins attract extra attention as promising biotechnological tool. Hence, the history, characteristics, and classification of bacteriocins are described in this review. Furthermore, the main difference between bacteriocins and other antimicrobial peptides is clarified. Also, bacteriocins biosynthesis and identified modes of action are elucidated. Additionally, current and potential applications of bacteriocins in food and medical fields are highlighted. Finally, future perspectives concerning studying bacteriocins and their applications are discussed.

Global systematic review and meta-analysis on prevalence and concentration of aflatoxins in peanuts oil and probabilistic risk assessment

Exposure to mycotoxins in food is largely unavoidable, and concerns about their health effects are growing. Consumption of vegetable oils such as peanuts oil has increased, hence several studies have been conducted on concentration of aflatoxins (AFs) in peanuts oil. Search was performed in Scopus and PubMed databases on prevalence and concentration of AFs in peanuts oil from 1 January 2005 to 15 April 29, 2022. Prevalence and concentration of AFs in peanuts oil was meta-analyzed based on country and type of AFs subgroups. In addition, health risk was calculated using monte carlo simulation method. Pooled prevalence of AFB1 in peanuts oil was 47.9%; AFB2, 46.45%; AFG1, 46.92% and AFG2, 54.01%. The Overall prevalence of AFTs was 49.30%, 95%CI (35.80-62.84%). Pooled concentration of AFB1 in peanuts oil was 2.30 μg/kg; AFB2, 0.77 μg/kg; AFG1, 0.07 μg/kg; AFG1, 0.28 μg/kg. The sort of country based on mean of MOEs in the adults consumers was Japan (47,059) > China (17,670) > Ethiopia (7,398) > Sudan (6,974) > USA (1,012) and sort of country based on mean of MOEs in the children was Japan (120,994) > China (46,991) > Ethiopia (19,251) > Sudan (18,200) > USA (2,620). Therefore, adults consumers were in considerable health risk in Ethiopia, Sudan and USA and for children in USA (MOE < 10,000).

Potential Impact of Combined Inhibition by Bacteriocins and Chemical Substances of Foodborne Pathogenic and Spoilage Bacteria: A Review

In recent years, food safety caused by foodborne pathogens and spoilage bacteria has become a major public health problem worldwide. Bacteriocins are a kind of antibacterial peptide synthesized by microbial ribosomes, and are widely used as food preservatives. However, when used individually bacteriocins may have limitations such as high cost of isolation and purification, narrow inhibitory spectrum, easy degradation by enzymes, and vulnerability to complex food environments. Numerous studies have demonstrated that co-treatment with bacteriocins and a variety of chemical substances can have synergistic antibacterial effects on spoilage microorganisms and foodborne pathogens, effectively prolonging the shelf life of food and ensuring food safety. Therefore, this paper systematically summarizes the synergistic bacteriostatic strategies of bacteriocins in combination with chemical substances such as essential oils, plant extracts, and organic acids. The impacts of bacteriocins when used individually and in combination with other chemical substances on different food substrates are clarified, and bacteriocin-chemical substance compositions that enhance antibacterial effectiveness and reduce the potential negative effects of chemical preservatives are highlighted and discussed. Combined treatments involving bacteriocins and different kinds of chemical substances are expected to be a promising new antibacterial method and to become widely used in both the food industry and biological medicine.

Microbial Inhibition by UV Radiation Combined with Nisin and Shelf-Life Extension of Tangerine Juice during Refrigerated Storage

This study evaluated the efficiency of UV radiation doses (4.68-149.76 J/cm²) and nisin (50-200 ppm) and their combination in comparison with thermal pasteurization on the microbial inhibition kinetics and physicochemical properties of tangerine juice. It was noted that UV-149.76 J/cm² and nisin (NS) at 200 ppm in conjunction exhibited the highest log reduction in spoilage and pathogenic microbes including Escherichia coli, Lactiplantibacillus plantarum, and Saccharomyces cerevisiae, yeast and molds, and total plate count in tangerine juice. Additionally, the first-order kinetic model provides a better fit for spoilage and pathogenic strains compared with the zero-order model (higher coefficient of determination, R²), particularly for E. coli. UV and NS showed insignificant effects (p > 0.05) on pH, TSS, and TA values compared with pasteurization. However, there were notable differences observed in color analysis, total phenolic compound, total flavonoid content, vitamin C, carotenoid content, and antioxidant activity using DPPH and FRAP assays. The optimized UV + NS samples were subjected to refrigerated storage for 21 days. The results revealed that during the entire storage period, the pH values and the TSS values slightly decreased, and the TA values increased in the treated samples. The UV + NS treatment insignificantly impacted the color properties. The total phenolic, total flavonoid, and carotenoid contents, and vitamin C decreased over time for all sample treatments, whereas the antioxidant properties exhibited varying outcomes, compared with an untreated control and pasteurization. Therefore, UV radiation and nisin (UV-149.76 J/cm² + NS-200 ppm) in combination could serve as a viable alternative to traditional heat pasteurization of fruit juice during cold storage.

Synergistic Effect of Combination of Various Microbial Hurdles in the Biopreservation of Meat and Meat Products—Systematic Review

The control of spoilage microorganisms and foodborne pathogens in meat and meat products is a challenge for food producers, which potentially can be overcome through the combined use of biopreservatives, in the form of a mix of various microbial hurdles. The objective of this work is to systematically review the available knowledge to reveal whether various microbial hurdles applied in combination can pose an effective decontamination strategy for meat and meat products. PubMed, Web of Science, and Scopus were utilized to identify and evaluate studies through February 2023. Search results yielded 45 articles that met the inclusion criteria. The most common meat biopreservatives were combinations of various starter cultures (24 studies), and the use of mixtures of non-starter protective cultures (13 studies). In addition, studies evaluating antimicrobial combinations of bacteriocins with other bacteriocins, BLIS (bacteriocin-like inhibitory substance), non-starter protective cultures, reuterin, and S-layer protein were included in the review (7 studies). In one study, a biopreservative mixture comprised antifungal protein PgAFP and protective cultures. The literature search revealed a positive effect, in most of the included studies, of the combination of various bacterial antimicrobials in inhibiting the growth of pathogenic and spoilage bacteria in meat products. The main advantages of the synergistic effect achieved were: (1) the induction of a stronger antimicrobial effect, (2) the extension of the spectrum of antibacterial action, and (3) the prevention of the regrowth of undesirable microorganisms. Although further research is required in this area, the combination of various microbial hurdles can pose a green and valuable biopreservation approach for maintaining the safety and quality of meat products.

Evaluation of Commercial Anti-Listerial Products for Improvement of Food Safety in Ready-to-Eat Meat and Dairy Products

In ready-to-eat products, such as cooked ham, fresh cheese, and fuet in which Listeria monocytogenes is a concern, the use of biopreservation techniques represents an additional hurdle to inhibit pathogen growth during storage. The objective of this study was to apply several biopreservation techniques in three different food matrices to reduce the growth of Listeria innocua, used as a surrogate of L. monocytogenes. Several lactic acid bacteria, the bacteriocin nisin, the bacteriophage PhageGuard Listex^TM P100, and the enzyme lysozyme were evaluated. Cooked ham treated with the bacteriophage PhageGuard Listex^TM at 0.5% or with the lactic acid bacteria SafePro^® B-SF-43 (25 g/100 kg) reduced L. innocua population to below the detection limit after 7 days of storage (4 °C plus modified atmosphere packaging). In fresh cheese, the application of PhageGuard Listex^TM at 0.2 and 0.5% reduced L. innocua counts by more than 3.4 logarithmic units after 6 days at 4 °C. In fuet, the 1.0% of PhageGuard Listex^TM reduced L. innocua population by 0.7 ± 0.2 logarithmic units in front of control with no significant differences to other evaluated biopreservative agents. The present results confirm that the application of biopreservation techniques was able to inhibit L. innocua in fuet, cooked ham, and fresh cheese, and suggest that the type of food matrix and its physicochemical characteristics influence the biopreservative efficacy.

Effect of Nanoemulsion Containing Enterocin GR17 and Cinnamaldehyde on Microbiological, Physicochemical and Sensory Properties and Shelf Life of Liquid-Smoked Salmon Fillets

The spoilage of liquid-smoked salmon represented a serious restriction for shelf life, due to the loss of taste, smell, color and consistency in product quality. The objective of this study was to investigate the feasibility of applying a nanoemulsion delivery system co-encapsulated enterocin Gr17 and essential oils (EOs) to the refrigerated storage of liquid-smoked salmon. The synergistic inhibiting effects of enterocin Gr17 and EOs were evaluated, a nanoemulsion delivery system with the optimal combination was developed, and the evolution of the microbiological, physicochemical, and sensory properties of liquid-smoked salmon fillets were analyzed during a 49-day period of refrigerated storage. The results showed that the combination of enterocin Gr17 and cinnamaldehyde essential oil (CEO) displayed the strongest synergistic inhibiting effect on foodborne pathogens. A nanoemulsion system incorporating enterocin Gr17 and CEO was successfully developed and presented a broad spectrum of activity against most of the tested bacteria. A nanoemulsion system incorporating enterocin Gr17 and CEO (CO-NE) could significantly inhibit the growth of microflora, suppress the accumulation of total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substance (TBARS), and maintain better color, texture, and sensory profiles during smoked salmon storage at 4 °C. Overall, from a microbiological, physicochemical, and sensory point of view, the CO-NE treatment could extend the shelf life to 42 days and maintain the relatively low TVB-N value (≤15.38 mg/100 g), TBARS value (≤2.51 mg MDA/kg), as well as a relatively high sensory score (≥5.83) during the whole storage period. Hence, a nanoemulsion system incorporating enterocin Gr17 and CEO could be a promising bio-preservative technology and alternative to the conventional processes used for improving the safety and quality of chilled liquid-smoked salmon.

Bio-photoelectrochemical degradation, and photocatalysis process by the fabrication of copper oxide/zinc cadmium sulfide heterojunction nanocomposites: Mechanism, microbial community and antifungal analysis

In this work, the fabrication of the CuO on ZnCdS as a heterojunction nanocomposites were conducted by hydrothermal method and the synthesis method was confirmed by the XRD, XPS, EDS, UV-vis spectrum analysis. The CuO/ZnCdS was used as a photocathode in the bio-photoelectrochemical system (BPES) for tetracycline (TC) degradation under solar irradiation. The CuO/ZnCdS photocathode indicated substantial photocatalytic efficiency for TC degradation, due to the fast separation and transfer of photogenerated carriers. The ESR test evaluates the mechanism of degradation, and shows that ·OH, and ·O₂^- were contributed to TC degradation. The TC degradation was 1.59 times higher than the unilluminated process (98.72% vs 61.71). The photocatalysis test shows that the TC was degraded about 90.5% in 1.5 h. Then, the synthesized CuO/ZnCdS nanocomposites were studied for the biological application such as antifungal activities. CuO/ZnCdS nanocomposites depicted substantial antimicrobial activity versus Candida-albicans by in vitro process. Therefore, this study suggests the novel system for the antibiotics degradation, and as antifungal application.

The concentration of potentially toxic elements (PTEs) in the coffee products: a systematic review and meta-analysis

Coffee is one of the most consumed products globally, and its contamination with potentially toxic elements (PTEs) occurs throughout the production chain and production. Therefore, the current meta-analysis study aimed to estimate the concentration of essential elements (Cu and Co) and the contamination of PTEs (Ni, Cr, Pb, As, and Cd) in coffee. The recommended databases, including PubMed, Scopus, and ScienceDirect, were investigated to collect data regarding the contamination of PTEs in coffee products from 2010 to 2021. Among 644 retrieved citations in the identification step, 34 articles were included in the meta-analysis. The pooled mean concentration of essential elements in coffee products is much higher than that of toxic elements (Co (447.106 µg/kg, 95% CI: 445.695-448.518 µg/kg) > Ni (324.175 µg/kg, 95% CI: 322.072-326.278 µg/kg) > Cu (136.171 µg/kg, 95% CI: 134.840-137.503 µg/kg) > Cr (106.865 µg/kg, 95% CI: 105.309-108.421 µg/kg) > Pb (21.027 µg/kg, 95% CI: 20.824-21.231 µg/kg) > As (3.158 µg/kg, 95% CI: 3.097-3.219 µg/kg) > Cd (0.308 µg/kg; 95% CI: 0.284-0.332 µg/kg)). Results showed high differences between pooled concentrations of all PTEs in coffee products of different countries.

A comprehensive review of microorganism-derived cyclic peptides: Bioactive functions and food safety applications

Cyclic peptides possess advanced structural characteristics of stability and play a vital role in medical treatment and agriculture. However, the biological functions of microorganism-derived cyclic peptides (MDCPs) and their applications in food industry were relatively absent. MDCPs are derived from extensive fermented food or soil. In this review, the synthesis approaches and structural characteristics are overviewed, while the interrelationship between bioactivities and functions is emphasized. This review summarizes the bioactivities of MDCPs from in vitro to in vivo, including antimicrobial activities, immune regulation, and antiviral cell activation. Their multiple functions as well as applications during food product processing, packaging, and storage are also comprehensively reviewed. Remarkably, some potential risks and cytotoxicity of MDCPs are also critically discussed. Moreover, future applications of MDCPs in the development of novel food additives and bioengineering materials are organized. Based on this review of native MDCPs, it is noteworthy that expected improvements of synthetic cyclic peptides in bioactive properties present potential valuable applications in future food, including artificial meat.

Lactic Acid Bacteria and Bacteriocins: Novel Biotechnological Approach for Biopreservation of Meat and Meat Products

Meat and meat products are perishable in nature, and easily susceptible to microbial contamination and chemical deterioration. This not only results in an increased risk to health of consumers, but also causes economic loss to the meat industry. Some microorganisms of the lactic acid bacteria (LAB) group and their ribosomal-synthesized antimicrobial peptides-especially bacteriocins-can be used as a natural preservative, and an alternative to chemical preservatives in meat industry. Purified or partially purified bacteriocins can be used as a food additive or incorporated in active packaging, while bacteriocin-producing cells could be added as starter or protective cultures for fermented meats. Large-scale applications of bacteriocins are limited, however, mainly due to the narrow antimicrobial spectrum and varying stability in different food matrixes. To overcome these limitations, bioengineering and biotechnological techniques are being employed to combine two or more classes of bacteriocins and develop novel bacteriocins with high efficacy. These approaches, in combination with hurdle concepts (active packaging), provide adequate safety by reducing the pathogenicity of spoilage microorganisms, improving sensory characteristics (e.g., desirable flavor, texture, aroma) and enhancing the shelf life of meat-based products. In this review, the biosynthesis of different classes of LAB bacteriocins, their mechanism of action and their role in the preservation of meats and meat products are reviewed.

Antiviral COVID-19 protein and molecular docking: In silico characterization of various antiviral compounds extracted from Arisaema jacquemontii Blume

Arisaema jacquemontii Blume is a highly medicinal and poisonous plant belong to the family Araceae. It is used to treat several deadly diseases, including viral infections. It has antioxidant, anti-cancerous, antimalarial, anti-vermicidal, and antiviral activities. Therefore, five parts of the Arisaema jacquemontii Blume plant, such as leaf, seed, stem, pulp, and rhizome extract, were evaluated for metabolic and in silico characterization of probable compounds using gas chromatography-mass spectrometry (GC-MS) analysis. A total of 22 compounds were isolated from the methanolic extracts of A. jacquemontii Blume. A selected antiviral COVID-19 protein i.e., protease (6LU7) was docked against the obtained compounds. Different affinities were obtained through various compounds. The best results were shown by three different compounds identified in the rhizome. The maximum binding affinity of these compounds is 8.1 kJ/mol. Molecular docking (MD) indicate that these molecules have the highest binding energies and hydrogen bonding interactions. The binding mode of interaction was discovered to be reasonably effective for counteracting the SARS virus COVID-19. The findings of this study could be extremely useful in the development of more phytochemical-based COVID-19 therapeutics.

Dynamic grafting of carboxylates onto poly(vinyl alcohol) polymers for supramolecularly-crosslinked hydrogel formation

Supramolecular hydrogels have attracted considerable interest due to their unique stimuli-responsive and self-healing properties. However, these hydrogel systems are usually achieved by covalent grafting of supramolecular units onto the polymer backbone, which in turn limits their reprocessability. Herein, we prepared a supramolecular hydrogel system by forming dynamic covalent crosslinks between 4-carboxyphenylboronic acid (CPBA) and polyvinyl alcohol (PVA). The system was then further crosslinked with either calcium ions or branched polyethylenimine (PEI) to generate hydrogels with distinctly different properties. Incorporation of calcium ions resulted in the formation of hydrogels with higher storage modulus of 7290 Pa but without self-healing properties. On the other hand, PEI-crosslinked hydrogel (PVA-CPBA-PEI) exhibited >2000% critical strain value, demonstrated high stability over 52 days and showed sustained antibacterial effect. A combination of supramolecular interactions and dynamic covalent crosslinks can be an alternate strategy to fabricate next generation hydrogel materials.

Optimization of the Quality of Chestnut Rose Jiaosu Compound Beverage Based on Probiotic Strains and Fermentation Technology

Chestnut rose is an endemic plant in Guizhou Province, China, also known as seedless prickly pear, rich in mineral elements, vitamin C, and flavonoids. With chestnut rose as the main raw material, with grapes, apples, and other fruits as auxiliary ingredients, through the technical process of deastringency, sterilization, fermentation, blending, and other technical processes to obtain the composite beverage, known as a chestnut rose jiaosu compound beverage, it is hereinafter referred to as CRJCB. The CRJCB fermented from chestnut rose juice is nutritious and has a variety of health effects, and the flavor is unique, with good color, aroma, and taste, which is a new type of beverage. However, at present, the fermentation related technology of CRJCB is not perfect, resulting in its low quality, which seriously restricts the industrialization development of CRJCB. In order to improve the quality of the jiaosu compound beverage, probiotics such as Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus casei, Lactobacillus royale (Lactobacillus reuteri), Lactobacillus acidophilus, and Streptococcus thermophilus, etc., were used. The chestnut rose as the main raw material was used for the fermentation, and grapes, apples, and sugar were used as auxiliary materials to carry out the research on the fermentation of single or mixed probiotics. The key fermentation processes affecting the quality of the jiaosu, such as juice preparation, deastringency of chestnut rose juice, fermentation temperature and time, sugar addition, and taste mixing of the jiaosu, were optimized. The optimized ratio, fermentation process parameters, and strains of probiotics of compound beverage with chestnut rose jiaosu, with high quality, were obtained. The experimental results showed that the SOD enzyme activity value was 167.7 U·ml−1, the vitamin C content was 1154.5 mg/100 mL, the soluble solids content was 5.80%, and the nitrite content was 89.8 mg/kg in the compound beverage with chestnut rose jiaosu, obtained by using the optimized ratio and fermentation process parameters proposed in this paper. The development and utilization of chestnut rose resources provide a new idea and is of great significance in promoting the development of the chestnut rose industry.

Facile synthesis of Cu NPs@Fe3O4-lignosulfonate: Study of catalytic and antibacterial/antioxidant activities

Environmental pollution is one of the important concerns for human health. There are different types of pollutants and techniques to eliminate them from the environment. We hereby report an efficient method for the remediation of environmental contaminants through the catalytic reduction of the selected pollutants. A green method has been developed for the immobilization of copper nanoparticles on magnetic lignosulfonate (Cu NPs@Fe₃O₄-LS) using the aqueous extract of Filago arvensis L. as a non-toxic reducing and stabilizing agent. The characterization of the prepared Cu NPs@Fe₃O₄-LS was achieved by vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), high resolution TEM (HRTEM), X-ray diffraction (XRD), scanning TEM (STEM), thermogravimetry-differential thermal analysis (TG/DTA), fast Fourier transform (FFT), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron (XPS) analyses. The synthesized Cu NPs@Fe₃O₄-LS was applied as a magnetic and green catalyst in the reduction of Congo Red (CR), 4-nitrophenol (4-NP), and methylene blue (MB). The progress of the reduction reactions was monitored by UV-Vis spectroscopy. Finally, the biological properties of the Cu NPs@Fe₃O₄-LS were investigated. The prepared catalyst demonstrated excellent catalytic efficiency in the reduction of CR, 4-NP, and MB in the presence of sodium borohydride (NaBH₄) as the reducing agent. The appropriate magnetism of Cu NPs@Fe₃O₄-LS made its recovery very simple. The advantages of this process include a simple reaction set-up, high and catalytic antibacterial/antioxidant activities, short reaction time, environmentally friendliness, high stability, and easy separation of the catalyst. In addition, the prepared Cu NPs@Fe₃O₄-LS could be reused for four cycles with no significant decline in performance.

Probiotic-Based Bacteriocin: Immunity Supplementation Against Viruses. An Updated Review

Viral infections are a major cause of severe, fatal diseases worldwide. Recently, these infections have increased due to demanding contextual circumstances, such as environmental changes, increased migration of people and product distribution, rapid demographic changes, and outbreaks of novel viruses, including the COVID-19 outbreak. Internal variables that influence viral immunity have received attention along with these external causes to avert such novel viral outbreaks. The gastrointestinal microbiome (GIM), particularly the present probiotics, plays a vital role in the host immune system by mediating host protective immunity and acting as an immune regulator. Bacteriocins possess numerous health benefits and exhibit antagonistic activity against enteric pathogens and immunobiotics, thereby inhibiting viral infections. Moreover, disrupting the homeostasis of the GIM/host immune system negatively affects viral immunity. The interactions between bacteriocins and infectious viruses, particularly in COVID-19, through improved host immunity and physiology are complex and have not yet been studied, although several studies have proven that bacteriocins influence the outcomes of viral infections. However, the complex transmission to the affected sites and siRNA defense against nuclease digestion lead to challenging clinical trials. Additionally, bacteriocins are well known for their biofunctional properties and underlying mechanisms in the treatment of bacterial and fungal infections. However, few studies have shown the role of probiotics-derived bacteriocin against viral infections. Thus, based on the results of the previous studies, this review lays out a road map for future studies on bacteriocins for treating viral infections.

Antioxidant, Cytotoxic, and Antimicrobial Potential of Silver Nanoparticles Synthesized using Tradescantia pallida Extract

Silver nanoparticles have received much attention, due to their wide range of biological applications as an alternative therapy for disease conditions utilizing the nanobiotechnology domain for synthesis. The current study was performed to examine the antioxidant, anticancer, antibacterial, and antifungal potential of biosynthesized silver nanoparticles (TpAgNPs) using plant extract. The TpAgNPs were produced by reacting the Tradescantia pallida extract and AgNO₃ solution in nine various concentration ratios subjected to bioactivities profiling. According to the current findings, plant extract comprising phenolics, flavonoids, and especially anthocyanins played a critical role in the production of TpAgNPs. UV–visible spectroscopy also validated the TpAgNP formation in the peak range of 401–441 nm. Further, the silver ion stabilization by phytochemicals, face-centered cubic structure, crystal size, and spherical morphology of TpAgNPs were analyzed by FTIR, XRD, and SEM. Among all TpAgNPs, the biosynthesized TpAgNP6 with a medium concentration ratio (5:10) and the plant extract had effective antioxidant potentials of 77.2 ± 1.0% and 45.1 ± 0.5% free radical scavenging activity, respectively. The cytotoxic activity of TpAgNP6 in comparison to plant extract for the rhabdomyosarcoma cell line was significantly the lowest with IC₅₀ values of 81.5 ± 1.9 and 90.59 ± 1.6 μg/ml and cell viability % of 24.3 ± 1.62 and 27.4 ± 1.05, respectively. The antibacterial and antifungal results of TpAgNPs revealed significant improvement in comparison to plant extract, i.e., minimum inhibition concentration (MIC) 64 μg/ml against Gram-negative Pseudomonas aeruginosa while, in the case of antifungal assay, TpAgNP6 was active against Candida parapsilosis. These TpAgNPs play a crucial role in determining the therapeutic potential of T. pallida due to their biological efficacy.

Nickel oxide nanoparticles synthesis using plant extract and evaluation of their antibacterial effects on Streptococcus mutans

Dental decay is known in the world as the most common human infectious disease. Ascending process of dental caries index in the world shows the failure of oral disease prevention. Streptococcus mutans bacteria cause acid damage and tooth decay by producing acid over time. Nanomaterials with suitable functionality, high permeability, extremely large surface area, significant reactivity, unique mechanical features, and non-bacterial resistance can be considered as promising agents for antimicrobial and antiviral applications. In this study, nickel oxide (NiO) nanoparticles with size range from 2 to 16 nm containing Stevia natural sweetener were eco-friendly synthesized via a simple method. Additionally, their various concentrations were evaluated on S. mutans bacteria by applying the broth dilution method. The results demonstrated that these spherical NiO nanoparticles had efficient bacteriostatic activity on this gram-positive coccus.

Antimicrobial effects of Cynara scolymus essential oil: In vitro analysis

By benefits of using silicon and vermicompost based biofertilizers and also induction of drought stress for growing more efficient medicinal plants, we investigated such issues on growing Cynara scolymus (C. scolymus), as one of the most significant edible medicinal plants. In this regard, the antimicrobial effects of grown C. scolymus essential oil was investigated against some foodborne pathogens. Different concentrations of silicon and vermicompost with and without drought stress were considered for growing the plant and the extracted essential oils were extracted to examine their antimicrobial effects against different bacterial agents. Using vermicompost and silicon and 50% moisture discharge yielded significant increase in the mean diameter of growth inhibition zone and significant decrease in the minimum inhibitory concentration of tested bacteria (P <  0.05). The highest diameters of the inhibition zones of S. aureus, S. saprophyticus, P. aeruginosa, S. dysenteriae, and S. typhi were found for C. scolymus essential oil treated with 8 mmol silicon and conventional irrigation (14.92 mm), 4 mmol silicon and 50% moisture discharge (15.28 mm), 50% vermicompost and 50% moisture discharge (15.71 mm), 8 mmol silicon and conventional irrigation (17.34 mm) and 25% vermicompost, and 50% moisture discharge (15.48 mm), respectively. Antimicrobial effects of some treatments of C. scolymus were higher than some kinds of referenced antibiotics such as erythromycin. These findings could be used for the production of antibiotic drugs for specific purposes against certain bacteria.