Search Results (149)

Biofilms cause a variety of problems, such as food spoilage, food poisoning, infection, tooth decay, periodontal disease, and metal corrosion, so knowledge on biofilm prevention and removal is important. A detailed observation of the three-dimensional structure of biofilms on the nanoscale is expected to provide insight into this. In this study, we report on the successful in situ nanoscale observations of a marine bacterial biofilm on glass in phosphate buffer solution (PBS) using both scanning ion conductance microscopy (SICM) and confocal laser scanning microscopy (CLSM) over the same area. By observing the same area by SICM and CLSM, we were able to clarify the three-dimensional morphology of the biofilm, the arrangement of bacteria within the biofilm, and the difference in local ion conductivity within the biofilm simultaneously, which could not be achieved by observation using a microscope alone. Full article

Microbial contamination of food can lead to faster spoilage and infections. Therefore, disinfection processes are required that have a low detrimental effect on the nutritional content. Concerning radiation disinfection, two spectral ranges have recently become important. The Far-UVC spectral range, with a wavelength below 230 nm and visible violet light. In this study, leaf spinach was used to investigate the extent to which these radiations inactivate Escherichia coli, but also to determine if the vitamin C or chlorophyll content was reduced. Frozen spinach leaves (Spinacia oleracea) were contaminated with E. coli × pGLO and irradiated with either a 222 nm krypton chloride lamp or 405 nm LEDs. The achieved bacterial reduction was determined by plating the irradiated samples on agar plates and subsequent colony counting. The vitamin C concentration was determined by means of redox titration, and the concentrations of chlorophyll a and chlorophyll b were determined using spectrometry. Both irradiations exhibited a strong antimicrobial impact on E. coli. The average log reduction doses were about 19 mJ/cm² (222 nm) and 87 J/cm² (405 nm), respectively. The vitamin C concentration decreased by 30% (222 nm) or 20% (405 nm), and the chlorophyll concentrations decreased by about 25%. Both irradiation approaches are able to substantially reduce microorganisms on spinach leaves by two orders of magnitude, but this is associated with a reduction in the nutrient content. Full article

Microbial contamination is the leading cause of foodborne diseases and spoilage in food and personal care products. Previous studies by our group have demonstrated that vine tea extract (VTE) and dihydromyricetin (DMY) inhibit the growth of Escherichia coli. In this study, we further explored the inhibitory mechanisms of VTE and DMY against E. coli through a label-free proteomics approach. The proteomic analysis detected 130 and 81 differentially expressed proteins (DEPs) in E.coli following VTE and DMY treatment, respectively. The analysis indicated that VTE and DMY inhibit bacterial growth through multiple-target mechanisms. Specifically, they inhibit E. coli growth by disrupting the cationic antimicrobial peptide resistance pathway, amino acid biosynthesis and metabolism, and nucleotide metabolism. Additionally, VTE disrupts various secondary metabolic pathways, while DMY interferes with E. coli ribosome assembly and function, and disrupts cell membrane lipid homeostasis by interfering with fatty acid metabolism. RT-qPCR validation confirmed transcriptional alterations in genes encoding key target proteins. Molecular docking results indicated that DMY may affect bacterial protein synthesis, cationic antimicrobial peptide resistance, and transcriptional regulation by binding to target proteins such as RplB, RplV, LpxA, and YafC. In conclusion, this study systematically deciphered the multi-target inhibitory mechanisms of VTE and DMY against E. coli, providing a theoretical basis for developing plant-derived antimicrobial agents. Full article

Mangifera indica L. by-products obtained by three extraction methods from three cultivars (Keitt, Sensation and Gomera-3) were tested for their antibacterial properties against 20 bacterial species. These species were selected based on their relevance to winemaking processes (Acetobacter, Gluconobacter and Gluconacetobacter), fermented meat products (Staphylococcus) and human diseases (Pseudomonas, Escherichia, Shigella and Klebsiella). All mango by-product extracts showed antimicrobial activity in agar diffusion and broth microdilution experiments. However, differences in antimicrobial activity against acetic acid bacteria were detected between the peel extracts obtained from the two extraction processes. Furthermore, a wide range of minimum inhibitory concentration (MIC) data were found; Staphylococcus spp. (10 species) showed MICs between 1.0–240 mgGAE/mL and Acetobacter spp. (4 species) showed MICs between 1.7 and 200 mgGAE/mL. The most sensitive bacteria belonged to the staphylococcal species (MIC: 1 mgGAE/mL) and the most resistant was Gluconacetobacter saccharivorans (MIC > 400 mgGAE/mL). In general, there was no significant correlation between the phenolic compounds identified and the MIC values. The minimum bactericidal concentration (MBC) revealed that the mango extracts had a bacteriostatic effect. A simple and reliable method for the determination of MIC and MBC in microdilution assays with acetic acid bacteria was described. These results highlight the antibacterial properties of mango by-products against species associated with food spoilage microorganisms and human diseases. Full article

The rapid growth of world population and increase in living standards have led to an increase in the demand for high-quality, safe food. The Food and Agriculture Organization of the United Nations (FAO) estimates that by 2050 the demand for food will increase by 60%, and production of animal protein will increase by 1.7% a year, with meat production to increase by nearly 70%, dairy products by 55%, and aquaculture by as much as 90%. Microbial contamination of food is a significant problem for the accessibility of safe food which does not pose a threat to the life and health of consumers. Campylobacter, Salmonella, and Yersinia are responsible for thousands of food-borne infections in humans. Currently, numerous programs are being developed to combat pathogenic bacteria in the food supply chain, especially at the primary production stage. These approaches include physical, chemical, biological, and other strategies and methods used to inhibit the bacterial growth of bacteria or completely eliminate the pathogens from the food chain. Therefore, an extremely important goal is to provide safe food and control its quality by eliminating pathogenic and spoilage microorganisms. However, the use of chemicals in food preservation has negative effects for both the consumption values of food and the natural environment. Therefore, it seems absolutely necessary to implement measures utilizing the most environmentally friendly and effective techniques for controlling microbial contamination in food. There is a great need to develop ecological methods in food production which guarantee adequate safety. One of these methods is the use of bacteriophages (bacterial viruses) naturally occurring in the environment. Given the above, the aim of this study was to present the most natural, ecological, and alternative methods of food preservation with regard to the most common foodborne zoonotic bacteria. We also present methods for reducing the occurrence of microbial contamination in food, thus to produce maximally safe food for consumers. Full article

Besides meat, pig organs are traditionally consumed in Asia. However, they can be a source of food poisoning. Less is known about the microbiome associated with different organ meats and the inter-animal variation in the microbiomes of organs. The aim of this pilot study was to characterize and compare the bacterial composition in fresh pig meat and organs (i.e., tonsils, lungs, and spleen) and blood from several carcasses using 16S rRNA amplicon sequencing as a screening method. We also investigated how closely the bacterial composition of the meat and organ samples was related to the gut bacterial community and the bacterial communities on the hands of the workers at different positions during meat processing. Meat, organ, blood, and gut (cecum and feces) samples were collected from 12 carcasses in two batches (n = 6/batch), along with swab samples (n = 4/batch) from the hands of the workers at different positions along the processing chain, from which DNA was extracted. The results for the bacterial diversity showed that each sample type (meat, organ, and blood) comprised a unique taxonomic composition (p < 0.05). Moreover, the data confirmed great inter-animal and batch variation for the meat, organs, and blood, which is helpful information for implementing strategies to enhance hygiene measures at pig farms and slaughterhouses, and hence food safety and quality. The genera associated with food safety and spoilage, such as Anoxybacillus, Acinetobacter, Pseudomonas, Campylobacter, and Streptococcus, were also different between the meat, organs, and blood. The bacterial communities in the gut samples distinctly clustered from communities in the pig organs and meat, whereas some overlaps in community clusters between lung, meat, and hand samples existed. This study demonstrates that the spleen, tonsils, and lungs contained more bacterial genera that comprise pathogenic strains than meat cuts, supporting the need to monitor their microbiome composition as potential contamination sources for food safety and spoilage reasons. Full article

The human microbiome plays a critical role in health and disease, with recent innovations in microbiome research offering groundbreaking insights that could reshape the future of healthcare. This study explored emerging methodologies, such as long-read sequencing, culturomics, synthetic biology, machine learning, and AI-driven diagnostics, that are transforming the field of microbiome–host interactions. Unlike traditional broad-spectrum approaches, these tools enable precise interventions, such as detecting foodborne pathogens and remediating polluted soils for safer agriculture. This work highlights the integration of interdisciplinary approaches and non-animal models, such as 3D cultures and organ-on-a-chip technologies, which address the limitations of current research and present ethical, scalable alternatives for microbiome studies. Focusing on food safety and environmental health, we examine how microbial variability impacts pathogen control in food chains and ecosystem resilience, integrating socioeconomic and environmental factors. The study also emphasizes the need to expand beyond bacterial-focused microbiome research, advocating for the inclusion of fungi, viruses, and helminths to deepen our understanding of therapeutic microbial consortia. The combination of high-throughput sequencing, biosensors, bioinformatics, and machine learning drives precision strategies, such as reducing food spoilage and enhancing soil fertility, paving the way for sustainable food systems and environmental management. Hence, this work offers a comprehensive framework for advancing microbiome interventions, providing valuable insights for researchers and professionals navigating this rapidly evolving field. Full article

High-throughput and portable sensor technologies are increasingly used in food production/distribution tasks as rapid and non-invasive platforms offering real-time or near real-time monitoring of quality and safety. These are often coupled with analytical techniques, including machine learning, for the estimation of sample quality and safety through monitoring of key physical attributes. However, the developed predictive models often show varying degrees of accuracy, depending on food type, storage conditions, sensor platform, and sample sizes. This work explores various fusion approaches for potential predictive enhancement, through the summation of information gathered from different observational spaces: infrared spectroscopy is supplemented with multispectral imaging for the prediction of chicken and beef spoilage through the estimation of bacterial counts in differing environmental conditions. For most circumstances, at least one of the fusion methodologies outperformed single-sensor models in prediction accuracy. Improvement in aerobic, vacuum, and mixed aerobic/vacuum chicken spoilage scenarios was observed, with performance enhanced by up to 15%. The improved cross-batch performance of these models proves an enhanced model robustness using the presented multi-sensor fusion approach. The batch-based results were corroborated with a repeated nested cross-validation approach, to give an out-of-sample generalised view of model performance across the whole dataset. Overall, this work suggests potential avenues for performance improvements in real-world, minimally invasive food monitoring scenarios. Full article

This study reports the synthesis and characterization of a novel carboxymethyl cellulose–N-fullerene–g-poly(co-acrylamido-2-methyl-1-propane sulfonic acid) (CMC–N-fullerene–AMPS) hydrogel for potential application in biosensing within food packaging. The hydrogel was synthesized via free radical polymerization and characterized using FTIR, SEM, and fluorescence microscopy. FTIR analysis confirmed the successful grafting of AMPS and incorporation of N-fullerenes, indicated by characteristic peaks and a shift in the N–H/O–H stretching frequency. Density Functional Theory (DFT) calculations revealed that the CMC–N-fullerene–AMPS hydrogel exhibited higher stability and a lower band gap energy (0.0871 eV) compared to the CMC–AMPS hydrogel, which means a high reactivity of CMC–N-fullerene–AMPS. The incorporation of N-fullerenes significantly enhanced the hydrogel’s antibacterial activity, demonstrating a 22 mm inhibition zone against E. coli and a 24 mm zone against S. aureus, suggesting potential for active food packaging applications. Critically, the hydrogel displayed a unique “turn-on” fluorescence response in the presence of bacteria, with distinct color changes observed upon interaction with E. coli (orange-red) and S. aureus (bright green). This fluorescence enhancement, coupled with the porous morphology observed via SEM (pore size 377–931 µm), suggests the potential of this hydrogel as a sensing platform for bacterial contamination within food packaging. These combined properties of enhanced antibacterial activity and a distinct, bacteria-induced fluorescence signal make the CMC–N-fullerene–AMPS hydrogel a promising candidate for developing intelligent food packaging materials capable of detecting bacterial spoilage. Full article

The influence of high-pressure processing (HPP) at 200, 400, and 600 MPa on spoilage bacterial diversity, microbial load, and chemical and sensory properties of the precooked edible portion of baby clam (PC-EP) was investigated. HPP at 400 MPa for 4 min (400 MPa) significantly prolonged shelf life and sensory acceptability up to 12 days, maintaining a total viable count (TVC) below 6 log CFU/g. In contrast, the TVC of both the control (without HPP treatment) and 200 MPa-treated samples exceeded this limit by day 0 and 3, respectively. The 400 MPa-treated samples showed a reduced load of psychrophilic bacteria, Aeromonas species, and lactic acid bacteria over 12 days. Additionally, coincidentally lower total volatile base and trimethylamine levels confirmed the good quality of HPP-treated PC-EP. Based on next-generation sequencing, a significantly lower microbial diversity index was found in the 400 MPa-treated samples, and it was dominated by Carnobacterium, Lactococcus, and Psychrobacter on day 12. In contrast, the control harbored spoilage bacteria, including Lactococcus, Aeromonas, Shewanella, and Pseudomonas, which correlated with higher acetic acid and acetoin levels as confirmed by HS-SPME-GC-EI/MS. These findings demonstrated that HPP at 400 MPa for 4 min was an effective non-thermal preservation method, extending the shelf life of PC-EP by inhibiting spoilage bacteria. Full article

Food contamination by pathogenic and spoilage bacteria causes approximately 47 million cases of foodborne diseases in the United States and leads to tons of food spoilage, worsening the food loss situation worldwide. In addition, conventional preservation treatments implemented in the food industry decrease food’s nutritional and organoleptic quality. Therefore, there is a need for new alternatives to counteract food contamination without altering its characteristics. Endolysins are a promising strategy due to their unique properties, such as host specificity, synergism with other antibacterial agents, mode of action, and low probability of resistance development. These characteristics differentiate them from other antibacterial agents used in the food industry. Endolysins are enzymes produced by bacteriophages during the process of bacterial infection and lysis. This review describes the advances related to endolysin application systems in food, considering their potential for food safety and an overview of the application conditions according to the type of food and bacteria to be controlled. We also highlight the need for new studies on endolysin encapsulation and prolongation of the action time in cases of outbreaks that allow obtaining key information to improve the application of endolysins in different food matrices during food processing and storage Full article

Nowadays, the spread of foodborne diseases and the growing concerns about antibiotic resistance have shifted the focus of researchers towards the use of substances of natural origin. Phenyllactic acid (PLA), a naturally produced compound, has already demonstrated antimicrobial properties against pathogenic microorganisms and those responsible for food spoilage. This study examines the antibacterial and antibiofilm properties of PLA against foodborne pathogens such as Salmonella enterica Derby and Escherichia coli O26. The study showed that PLA effectively inhibited both biofilm formation and bacterial planktonic growth, with minimal inhibitory concentrations (MICs) ranging from 2 to 2.75 mg mL⁻¹. A dose-dependent inhibition of biofilm formation was observed, reaching approximately 90% for Salmonella strains and 50% for E. coli at 1.5 mg mL⁻¹. The cytotoxicity evaluation on Caco-2 cells showed that PLA was well-tolerated at concentrations up to 2 mg mL⁻¹. PLA’s effectiveness was also demonstrated in real food matrices, where its application in minced beef stored at 4 °C significantly reduced microbial populations, unlike in untreated samples where bacterial counts increased. PLA showed a good ability to inhibit biofilm formation and eradicate a mature biofilm, measuring the total bacterial biofilm biomass. Additionally, PLA was found to be biocompatible in Caco-2 cells, confirming that it poses no health risk at the tested concentrations. The study also observed that PLA reduced bacterial adhesion to intestinal cells, suggesting its potential in preventing intestinal bacterial colonization. These results highlight PLA as a promising natural antimicrobial agent for food preservation, with potential applications in sustainable packaging and controlling microbial contamination in food processing. Future studies should further explore PLA’s long-term stability and its interactions in complex food environments. Full article

Poultry meat is the most consumed meat worldwide due to its low fat content, sensory qualities, and affordability. However, its rapid spoilage, especially when minced for products like hamburgers, is a challenge. Strategies such as sulfite addition or modified-atmosphere packaging (MAP) can help control spoilage and microbial growth. This study evaluated both approaches by analyzing bacterial development in poultry hamburgers through total viable counts and MALDI-TOF identification, combining food-pathogens detection. The addition of 5 mg/kg sulfites had a limited effect, whereas increasing CO₂ levels in the packaging significantly extended the shelf life by reducing the bacterial growth rates and prolonging the lag phases. The most affected bacteria were aerobic mesophilic and psychrotrophic bacteria, as well as Brochothrix thermosphacta. Carnobacterium spp. dominated the aerobic mesophilic group, while Enterobacter spp. was prevalent in Enterobacteriaceae and aerobic mesophilic isolates, highlighting its role in spoilage. Hafnia alvei was also relevant in the final spoilage stages. These results suggest the importance of these bacteria in poultry hamburger decay and demonstrate that MAP is an effective method to delay spoilage. Full article

Background/Objectives: The deterioration of food quality and safety is often linked to the presence of pathogenic and spoilage microorganisms. Postbiotics, including organic acids, enzymes, and bacteriocins produced by lactic acid bacteria (LAB), have emerged as promising next-generation food preservatives. This study investigates the biological and physicochemical properties of several postbiotic-based extracts (PBEs) comprising cell-free supernatant (CFS) and exopolysaccharide (EPS) fractions derived from three native probiotic strains: Lactiplantibacillus plantarum UTNGt2, Lactococcus lactis UTNGt28, and Weissella cibaria UTNGt21O. Methods: The antibacterial activity of these PBEs was assessed against multidrug-resistant Escherichia coli L1PEag1. Moreover, the antioxidant capacity and cytotoxicity along with the characterization of these formulations was assessed. Results: FU6 (CFS UTNGt28: EPS UTNGt2) and FU13 (CFS UTNGt21O) were found as the most potent formulations. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed dose- and time-dependent damage to the bacterial membrane and cell wall. FU6 exhibited superior antioxidant activity and lacked hemolytic effects, whereas both FU6 and FU13 induced cell-specific responses in HEK293 (human kidney) and HT-29 (intestinal mucus-producing) cell lines. Furthermore, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy identified characteristic absorption bands corresponding to proteins, lipids, carbohydrates, and nucleic acids, while proton nuclear magnetic resonance (¹H-NMR) spectroscopy revealed key monosaccharides, amino acids, and metabolites such as lactate and acetate within the extracts. Conclusions: FU6 and FU13 demonstrate potential as safe and effective postbiotic formulations at non-concentrated doses. However, further research is required to elucidate their molecular composition comprehensively and evaluate their applicability for broader and long-term use in food preservation and pharmaceutical development. Full article

Bacteriocins, ribosomally synthesized by bacteria, have long been recognized for their role in ensuring food safety and security due to their antibacterial effects against foodborne pathogens and spoilage bacteria. However, recent advancements have unveiled their expanding potential beyond food applications, with increasing evidence of their efficacy against clinically significant pathogenic bacteria, biofilm formation, viral infections, and even cancer. These emerging discoveries have continuously added new layers to the application of bacteriocins, extending their relevance from food preservation to broader human health interventions. To further harness this expanding potential, various innovative strategies have been developed to overcome traditional limitations associated with bacteriocin use. Instead of directly employing bacteriocins or bacteriocin-producing bacterial cultures, novel approaches, such as incorporating them into films and packaging materials or coupling them with nanoparticles, have demonstrated enhanced effectiveness. In this review, we examine the evolving landscape of bacteriocin applications and shed light on the expanding functional spectrum of bacteriocins for both food safety and human health, although some important challenges and limitations remain. By analyzing the recent literature and innovative technological advancements, we highlight how bacteriocins are continuously evolving, opening new frontiers for their use and reinforcing their significance beyond their conventional roles. Full article