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1.
Anal Bioanal Chem ; 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38878181

RESUMO

As a representative gas of food spoilage, the development of rapid hydrogen sulfide (H2S) analysis strategies for food safety control is in great demand. Despite traditional methods for H2S detection possessing great achievements, they are still incapable of meeting the requirement of portability and quantitative detection at the same time. Herein, a nanozyme catalysis pressure-powered sensing platform that enables visual quantification with the naked eye is proposed. In this methodology, Pt nanozyme inherits the catalase-like activity to facilitate the decomposition of H2O2 to O2, which can significantly improve the pressure in the closed container, further pushing the movement of indicator dye. Furthermore, H2S was found to effectively inhibit the catalytic activity of Pt nanozyme, indicating that the catalase-like activity of PtNPs may be regulated by varying concentrations of H2S. Therefore, by utilizing a self-designed pressure-powered microchannel device, the concentration of H2S was successfully converted into a distinct signal variation in distance. The effectiveness of the as-designed sensor in assessing the spoilage of red wine by H2S determination has been demonstrated. It exhibits a strong correlation between the change in dye distance and H2S concentration within the range of 1-250 µM, with a detection limit of 0.17 µM. This method is advantageous as it enhances the quantitative detection of H2S with the naked eye based on the portable pressure-powered sensing platform, as compared to traditional H2S biosensors. Such a pressure-powered distance variation platform would greatly broaden the application of H2S-based detection in food spoilage management.

2.
Lett Appl Microbiol ; 77(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38886121

RESUMO

Hafnia sp. was one of the specific spoilage bacteria in aquatic products, and the aim of the study was to investigate the inhibition ability of the silver nanoparticles (AgNPs) biosynthesis by an aqueous extract of Prunus persica leaves toward the spoilage-related virulence factors of Hafnia sp. The synthesized P-AgNPs were spherical, with a mean particle size of 36.3 nm and zeta potential of 21.8 ± 1.33 mV. In addition, the inhibition effects of P-AgNPs on the growth of two Hafnia sp. strains and their quorum sensing regulated virulence factors, such as the formation of biofilm, secretion of N-acetyl-homoserine lactone (AHLs), proteases, and exopolysaccharides, as well as their swarming and swimming motilities were evaluated. P-AgNPs had a minimum inhibitory concentration (MIC) of 64 µg ml-1 against the two Hafnia sp. strains. When the concentration of P-AgNPs was below MIC, it could inhibit the formation of biofilms by Hafnia sp at 8-32 µg ml-1, but it promoted the formation of biofilms by Hafnia sp at 0.5-4 µg ml-1. P-AgNPs exhibited diverse inhibiting effects on AHLs and protease production, swimming, and swarming motilities at various concentrations.


Assuntos
Antibacterianos , Biofilmes , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Extratos Vegetais , Folhas de Planta , Prunus persica , Percepção de Quorum , Prata , Percepção de Quorum/efeitos dos fármacos , Prata/farmacologia , Prata/química , Prata/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Folhas de Planta/microbiologia , Folhas de Planta/química , Nanopartículas Metálicas/química , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Antibacterianos/farmacologia , Prunus persica/microbiologia , Aizoaceae/química , Fatores de Virulência/metabolismo
3.
Mikrochim Acta ; 191(6): 354, 2024 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-38809328

RESUMO

A reversible optoelectronic nose is presented consisting of ten acid-base indicators incorporated into a starch-based film, covering a wide pH range. The starch substrate is odorless, biocompatible, flexible, and exhibits high tensile resistance. This optical artificial olfaction system was used to detect the early stages of food decomposition by exposing it to the volatile compounds produced during the spoialge process of three food products (beef, chicken, and pork). A smartphone was used to capture the color changes caused by intermolecular interactions between each dye and the emitted volatiles over time. Digital images were processed to generate a differential color map, which uses the observed color shifts to create a unique signature for each food product. To effectively discriminate among different samples and exposure times, we employed chemometric tools, including hierarchical cluster analysis (HCA) and principal component analysis (PCA). This approach detects food deterioration in a practical, cost-effective, and user-friendly manner, making it suitable for smart packaging. Additionally, the use of starch-based films in the food industry is preferable due to their biocompatibility and biodegradability characteristics.


Assuntos
Nariz Eletrônico , Embalagem de Alimentos , Amido , Amido/química , Animais , Galinhas , Suínos , Bovinos , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análise , Smartphone , Análise de Componente Principal
4.
Appl Environ Microbiol ; 89(6): e0012523, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37255457

RESUMO

Populations of microbial cells may resist environmental stress by maintaining a high population-median resistance (IC50) or, potentially, a high variability in resistance between individual cells (heteroresistance); where heteroresistance would allow certain cells to resist high stress, provided the population was sufficiently large to include resistant cells. This study sets out to test the hypothesis that both IC50 and heteroresistance may contribute to conventional minimal inhibitory concentration (MIC) determinations, using the example of spoilage-yeast resistance to the preservative sorbic acid. Across a panel of 26 diverse yeast species, both heteroresistance and particularly IC50 were positively correlated with predicted MIC. A focused panel of 29 different isolates of a particular spoilage yeast was also examined (isolates previously recorded as Zygosaccharomyces bailii, but genome resequencing revealing that several were in fact hybrid species, Z. parabailii and Z. pseudobailii). Applying a novel high-throughput assay for heteroresistance, it was found that IC50 but not heteroresistance was positively correlated with predicted MIC when considered across all isolates of this panel, but the heteroresistance-MIC interaction differed for the individual Zygosaccharomyces subspecies. Z. pseudobailii exhibited higher heteroresistance than Z. parabailii whereas the reverse was true for IC50, suggesting possible alternative strategies for achieving high MIC between subspecies. This work highlights the limitations of conventional MIC measurements due to the effect of heteroresistance in certain organisms, as the measured resistance can vary markedly with population (inoculum) size. IMPORTANCE Food spoilage by fungi is a leading cause of food waste, with specialized food spoilage yeasts capable of growth at preservative concentrations above the legal limit, in part due to heteroresistance allowing small subpopulations of cells to exhibit extreme preservative resistance. Whereas heteroresistance has been characterized in numerous ecological contexts, measuring this phenotype systematically and assessing its importance are not encompassed by conventional assay methods. The development here of a high-throughput method for measuring heteroresistance, amenable to automation, addresses this issue and has enabled characterization of the contribution that heteroresistance may make to conventional MIC measurements. We used the example of sorbic acid heteroresistance in spoilage yeasts like Zygosaccharomyces spp., but the approach is relevant to other fungi and other inhibitors, including antifungals. The work shows how median resistance, heteroresistance, and inoculum size should all be considered when selecting appropriate inhibitor doses in real-world antimicrobial applications such as food preservation.


Assuntos
Eliminação de Resíduos , Zygosaccharomyces , Ácido Sórbico , Alimentos , Leveduras , Testes de Sensibilidade Microbiana , Zygosaccharomyces/genética
5.
Crit Rev Biotechnol ; 43(2): 258-274, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35114869

RESUMO

Acid-resistant bacteria are more and more widely used in industrial production due to their unique acid-resistant properties. In order to survive in various acidic environments, acid-resistant bacteria have developed diverse protective mechanisms such as sensing acid stress and signal transduction, maintaining intracellular pH homeostasis by controlling the flow of H+, protecting and repairing biological macromolecules, metabolic modification, and cross-protection. Acid-resistant bacteria have broad biotechnological application prospects in the food field. The production of fermented foods with high acidity and acidophilic enzymes are the main applications of this kind of bacteria in the food industry. Their acid resistance modules can also be used to construct acid-resistant recombinant engineering strains for special purposes. However, they can also cause negative effects on foods, such as spoilage and toxicity. Herein, the aim of this paper is to summarize the research progress of molecular mechanisms against acid stress of acid-resistant bacteria. Moreover, their effects on the food industry were also discussed. It is useful to lay a foundation for broadening our understanding of the physiological metabolism of acid-resistant bacteria and better serving the food industry.


Assuntos
Bactérias , Biotecnologia , Bactérias/metabolismo , Ácidos/metabolismo , Indústria Alimentícia
6.
Anal Biochem ; 662: 114999, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36519741

RESUMO

Due to their ability to form extremely heat resistant spores, anaerobic bacteria are responsible for frequent food spoilage. The development of rapid and specific methods for the detection and quantification of spore contamination is therefore of major interest. In this paper, we describe for the first time the selection of aptamers specific to spores of Geobacillus stearothermophilus (Gbs), which induce flat sour spoilage in vegetable cans. Eighteen Spore-SELEX cycles were performed including 4 counter-selections with 12 bacteria commonly found in cannery. To optimise candidate amplification, PCR in emulsion was performed, and high-throughput sequencing analysis was applied to follow candidate evolution. Sequencing of aptamers from cycle 18 revealed 43 overrepresented sequences whose copy number exceeds 0.15% of the total obtained sequences. Within this group, the A01 aptamer presented a much higher enrichment with a relative abundance of 17.71%. Affinity and specificity for Gbs spores of the 10 most abundant candidates at cycle 18 were confirmed by PCR assay based on aptamer-spore complex formation and filtration step. Obtaining these aptamers is the starting point for the future development of biosensors dedicated to the detection of Gbs spores.


Assuntos
Aptâmeros de Nucleotídeos , Geobacillus stearothermophilus , Geobacillus stearothermophilus/genética , Esporos Bacterianos/genética , Bactérias , Alimentos , Reação em Cadeia da Polimerase , Aptâmeros de Nucleotídeos/genética , Técnica de Seleção de Aptâmeros
7.
Crit Rev Food Sci Nutr ; 63(23): 6393-6411, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35089844

RESUMO

Conventionally used petrochemical-based plastics are poorly degradable and cause severe environmental pollution. Alternatively, biopolymers (e.g., polysaccharides, proteins, lipids, and their blends) are biodegradable and environment-friendly, and thus their use in packaging technologies has been on the rise. Spoilage of food by mycotoxigenic fungi poses a severe threat to human and animal health. Hence, because of the adverse effects of synthetic preservatives, active packaging as an effective technique for controlling and decontaminating fungi and related mycotoxins has attracted considerable interest. The current review aims to provide an overview of the prevention of fungi and mycotoxins through active packaging. The impact of different additives on the antifungal and anti-mycotoxigenic functionality of packaging incorporating active films/coatings is also investigated. In addition, active packaging applications to control and decontaminate common fungi and mycotoxins in bakery products, cereal grains, fruits, nuts, and dairy products are also introduced. The results of recent studies have confirmed that biopolymer films and coatings incorporating antimicrobial agents provide great potential for controlling common fungi and mycotoxins and enhancing food quality and safety.


Assuntos
Anti-Infecciosos , Micotoxinas , Animais , Humanos , Fungos , Embalagem de Alimentos/métodos , Antifúngicos , Biopolímeros
8.
Crit Rev Food Sci Nutr ; : 1-18, 2023 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-38069682

RESUMO

Food spoilage bacteria (FSB) and multidrug-resistant (MDR) foodborne pathogens have emerged as one of the principal public health concerns in the twenty first century. The harmful effects of FSB lead to economic losses for the food industries. Similarly, MDR foodborne pathogens are accountable for multiple illnesses and pose a threat to consumers. Therefore, there is an urgent need to establish effective formulations for successful application against such microorganisms. In this context, the fusion of knowledge from biotechnology and nanotechnology can explore endless possibilities in the development of innovative formulations against FSB and foodborne pathogens. The current review critically examines the application of bacteriocins in the food industry and the use of nanomaterials to enhance the antimicrobial activity, stability, and precision in the target delivery of bacteriocins. This review also explores the technologies involved in the development of bacteriocin-based nanoformulations and their action against FSB and MDR foodborne pathogens, offering new possibilities in preservation technologies and addressing food safety issues in the food industry. The review highlights the challenges in the commercialization and technoeconomical feasibility of nanobacteriocin. Overall, it provides essential information and interpretation about nanotechnological advancements in bacteriocin formulation action against FSB and foodborne pathogens and future scopes.

9.
Lett Appl Microbiol ; 76(7)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37339913

RESUMO

Food degradation made by mycotoxigenic molds represents a significant challenge too food security. Postbiotics are associated with soluble compounds liberated by living bacterial cells or their construction release after lysis, and these metabolites offer the host biological action and specific physiological benefits. In this work, the postbiotics from tree strains of Lactobacillus spp. (Limosilactobacillus reuteri ATCC 367, Lacticaseibacillus casei431and Levilactobacillus brevisATCC) were lyophilized, filtered, and tested to evaluate the antimicrobial and anti-biofilm activity in vitro and milk against P. expansoum. Also, to assess the antioxidant efficacy and the free radical scavenging possibility of the postbiotic, DPPH, and ABTS + methods were used. Antimicrobial activity and biofilm removal activity of postbiotics depended on the Lactobacillus strains used. The minimum inhibitory concentration (MIC) of the prepared postbiotic was determined to be 70ug/ml. The lowest minimum effective concentration (MEC) of postbiotics were significantly differed, in the food matrix, and a low MEC index (100 mg/ml) was detected for postbiotic of L. brevis. Postbiotics derived from L. brevis showed the highest antimicrobial activity compared to L. casei and L. reuteri. The postbiotic extracted from Lactobacillus strain may have functional properties (potential antimicrobial and anti-biofilm) in vitro and food models.


Assuntos
Anti-Infecciosos , Limosilactobacillus reuteri , Penicillium , Lactobacillus/metabolismo , Antifúngicos/farmacologia , Penicillium/metabolismo , Anti-Infecciosos/farmacologia , Biofilmes
10.
Food Microbiol ; 109: 104151, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309448

RESUMO

We investigated the function of pyoverdine in the biofilm formation, motility, and spoilage potential of Pseudomonas fluorescens. We targeted and identified two major genes (pvdA and pvdE) that are involved in the biosynthesis of siderophores. We next constructed ΔpvdA and ΔpvdE mutants of P. fluorescens PF08 and found that the deletion of pyoverdine led to a biofilm-to-motivity transition as both ΔpvdA and ΔpvdE mutants displayed enhanced motility, reduced level of exopolysaccharides (EPSs), and attenuated biofilm formation. In addition, the lack of synthesis of pyoverdine promoted the spoilage of fish fillets stored at 4 °C. Based on the effect of pyoverdine deletion on the phenotype; we report that pyoverdine regulates the transcription levels of htpX, phoA, flip, flgA, and RpoS, suggesting that pyoverdine-mediated iron absorption may affect the regulation of flagellum and stress resistance. This study emphasizes the important role of pyoverdine in the formation of biofilm, motility, and spoilage of P. fluorescens PF08.


Assuntos
Pseudomonas fluorescens , Sideróforos , Animais , Pseudomonas fluorescens/genética , Biofilmes
11.
Food Microbiol ; 116: 104365, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37689419

RESUMO

This study investigated the combined effect of Ultraviolet (UV) light-emitting diode (LED) technology treatment with refrigerated storage of chicken breast meat over 7 days on Campylobacter jejuni, Salmonella enterica serovar Typhimurium, total viable counts (TVC) and total Enterobacteriaceae counts (TEC). An optimised UV-LED treatment at 280 nm for 6 min decreased inoculated S. Typhimurium and C. jejuni populations by 0.6-0.64 log CFU/g, and TVC and TEC population by 1-1.2 log CFU/g in chicken samples. During a 7-day storage at 4 °C, a 0.73 log reduction in C. jejuni was achieved compared with non-treated samples. Moreover, the UV-LED effectiveness to reduce TVC and TEC during refrigerated storage was compared with a conventional UV lamp and a similar efficiency was observed. The impact of UV-LED and UV lamp devices on the microbial community composition of chicken meat during storage was further examined using 16 S rRNA gene amplicon sequencing. Although similar bacterial reductions were observed for both technologies, the microbial communities were impacted differently. Treatment with the UV conventional lamp increased the proportion of Brochothrix spp. In meat samples, whilst Photobacterium spp. Levels were reduced.


Assuntos
Campylobacter , Microbiota , Animais , Galinhas , Raios Ultravioleta , Enterobacteriaceae , Salmonella typhimurium
12.
Food Microbiol ; 114: 104306, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37290880

RESUMO

Chicken meat is the most popularly consumed meat worldwide, with free-range and ethically produced meat a growing market among consumers. However, poultry is frequently contaminated with spoilage microbes and zoonotic pathogens which impact the shelf-life and safety of the raw product, constituting a health risk to consumers. The free-range broiler microbiota is subject to various influences during rearing such as direct exposure to the external environment and wildlife which are not experienced during conventional rearing practices. Using culture-based microbiology approaches, this study aimed to determine whether there is a detectable difference in the microbiota from conventional and free-range broilers from selected Irish processing plants. This was done through analysis of the microbiological status of bone-in chicken thighs over the duration of the meat shelf-life. It was found that the shelf-life of these products was 10 days from arrival in the laboratory, with no statistically significant difference (P > 0.05) evident between free-range and conventionally raised chicken meat. A significant difference, however, was established in the presence of pathogenesis-associated genera in different meat processors. These results reinforce past findings which indicate that the processing environment and storage during shelf-life are key determinants of the microflora of chicken products reaching the consumer.


Assuntos
Galinhas , Microbiota , Animais , Galinhas/microbiologia , Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Carne/microbiologia
13.
Food Microbiol ; 109: 104138, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309440

RESUMO

The bacterial diversity and load on equipment in food processing facilities is constantly influenced by raw material, water, air, and staff. Despite regular cleaning and disinfection, some bacteria may persist and thereby potentially compromise food quality and safety. Little is known about how bacterial communities in a new food processing facility gradually establish themselves. Here, the development of bacterial communities in a newly opened salmon processing plant was studied from the first day and during the first year of operation. To focus on the persisting bacterial communities, surface sampling was done on strategical sampling points after cleaning and disinfection. To study the diversity dynamics, isolates from selected sampling and time points were classified by Oxford Nanopore Technology-based rep-PCR amplicon sequencing (ON-rep-seq) supplemented by 16S rRNA gene or rpoD gene sequencing (for Pseudomonas). An overall increase in bacterial numbers was only observed for food-contact surfaces in the slaughter department, but not in filleting department, on non-food contact surfaces or on the fish. Changes in temporal and spatial diversity and community composition were observed and our approach revealed highly point-specific bacterial communities.


Assuntos
Microbiologia de Alimentos , Salmão , Animais , Bactérias , Manipulação de Alimentos , RNA Ribossômico 16S/genética , Microbiota
14.
Mikrochim Acta ; 190(6): 215, 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-37171648

RESUMO

The detection of biogenic amines released from degraded meats is an effective method for evaluating meat freshness. However, existing traditional methods like titration are deemed tedious, while the use of sophisticated analytical instruments is not amenable to field testing. Herein, a cyanostilbene-based fluorescent array was rapidly fabricated using macroarray synthesis on a cellulose paper surface to detect amines liberated from spoiled beef, fish, and chicken. The fluorescence changes of immobilized molecules from the interaction with gaseous amines were used to monitor changes in freshness levels. Thanks to the high-throughput nature of macroarray synthesis, a set of highly responsive molecules such as pyridinium and dicyanovinyl moieties were quickly revealed. Importantly, this method offers flexibility in sensing applications including (1) sensing by individual sensor molecules, where the fluorescence response correlated well with established titration methods, and (2) collective sensing whereby chemometric analysis was used to provide a cutoff of freshness with 73-100% accuracy depending on meat types. Overall, this study paves the way for a robust and cost-effective tool for monitoring meat freshness.


Assuntos
Aminas Biogênicas , Carne , Animais , Bovinos , Carne/análise , Aminas Biogênicas/análise , Corantes , Peixes , Galinhas
15.
Molecules ; 28(8)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37110618

RESUMO

The development of intelligent indicator film that can detect changes in food quality is a new trend in the food packaging field. The WPNFs-PU-ACN/Gly film was prepared based on whey protein isolate nanofibers (WPNFs). Anthocyanin (ACN) and glycerol (Gly) were used as the color indicator and the plasticizer, respectively, while pullulan (PU) was added to enhance mechanical properties of WPNFs-PU-ACN/Gly edible film. In the study, the addition of ACN improved the hydrophobicity and oxidation resistance of the indicator film; with an increase in pH, the color of the indicator film shifted from dark pink to grey, and its surface was uniform and smooth. Therefore, the WPNFs-PU-ACN/Gly edible film would be suitable for sensing the pH of salmon, which changes with deterioration, as the color change of ACN was completely consistent with fish pH. Furthermore, the color change after being exposed to grey was evaluated in conjunction with hardness, chewiness, and resilience of salmon as an indication. This shows that intelligent indicator film made of WPNFs, PU, ACN, and Gly could contribute to the development of safe food.


Assuntos
Filmes Comestíveis , Embalagem de Alimentos , Animais , Alimentos Marinhos , Peixes , Antocianinas/química , Concentração de Íons de Hidrogênio
16.
Compr Rev Food Sci Food Saf ; 22(2): 1257-1284, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36710649

RESUMO

Each year, 1.3 billion tons of food is lost due to spoilage or loss in the supply chain, accounting for approximately one third of global food production. This requires a manufacturer to provide accurate information on the shelf life of the food in each stage. Various models for monitoring food quality have been developed and applied to predict food shelf life. This review classified shelf life models and detailed the application background and characteristics of commonly used models to better understand the different uses and aspects of the commonly used models. In particular, the structural framework, application mechanisms, and numerical relationships of commonly used models were elaborated. In addition, the study focused on the application of commonly used models in the food field. Besides predicting the freshness index and remaining shelf life of food, the study addressed aspects such as food classification (maturity and damage) and content prediction. Finally, further promotion of shelf life models in the food field, use of multivariate analysis methods, and development of new models were foreseen. More reliable transportation, processing, and packaging methods could be screened out based on real-time food quality monitoring.


Assuntos
Qualidade dos Alimentos , Armazenamento de Alimentos
17.
BMC Genomics ; 23(1): 803, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36471243

RESUMO

BACKGROUND: Lentilactobacillus parabuchneri is of particular concern in fermented food bioprocessing due to causing unwanted gas formation, cracks, and off-flavor in fermented dairy foods. This species is also a known culprit of histamine poisonings because of decarboxylating histidine to histamine in ripening cheese. Twenty-eight genomes in NCBI GenBank were evaluated via comparative analysis to determine genomic diversity within this species and identify potential avenues for reducing health associated risks and economic losses in the food industry caused by these organisms. RESULT: Core genome-based phylogenetic analysis revealed four distinct major clades. Eight dairy isolates, two strains from an unknown source, and a saliva isolate formed the first clade. Three out of five strains clustered on clade 2 belonged to dairy, and the remaining two strains were isolated from the makgeolli and Korean effective microorganisms (KEM) complex. The third and fourth clade members were isolated from Tete de Moine and dairy-associated niches, respectively. Whole genome analysis on twenty-eight genomes showed ~ 40% of all CDS were conserved across entire strains proposing a considerable diversity among L. parabuchneri strains analyzed. After assigning CDS to their corresponding function, ~ 79% of all strains were predicted to carry putative intact prophages, and ~ 43% of the strains harbored at least one plasmid; however, all the strains were predicted to encode genomic island, insertion sequence, and CRISPR-Cas system. A type I-E CRISPR-Cas subgroup was identified in all the strains, with the exception of DSM15352, which carried a type II-A CRISPR-Cas system. Twenty strains were predicted to encode histidine decarboxylase gene cluster that belongs to not only dairy but also saliva, KEM complex, and unknown source. No bacteriocin-encoding gene(s) or antibiotic resistome was found in any of the L. parabuchneri strains screened. CONCLUSION: The findings of the present work provide in-depth knowledge of the genomics of L. parabuchneri by comparing twenty-eight genomes available to date. For example, the hdc gene cluster was generally reported in cheese isolates; however, our findings in the current work indicated that it could also be encoded in those strains isolated from saliva, KEM complex, and unknown source. We think prophages are critical mobile elements of L. parabuchneri genomes that could pave the way for developing novel tools to reduce the occurrence of this unwanted species in the food industry.


Assuntos
Genoma Bacteriano , Microbiota , Filogenia , Histamina , Saliva , Genômica , Prófagos
18.
Appl Environ Microbiol ; 88(4): e0168021, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-34910563

RESUMO

The marine environment presents great potential as a source of microorganisms that possess novel enzymes with unique activities and biochemical properties. Examples of such are the quorum-quenching (QQ) enzymes that hydrolyze bacterial quorum-sensing (QS) signaling molecules, such as N-acyl-homoserine lactones (AHLs). QS is a form of cell-to-cell communication that enables bacteria to synchronize gene expression in correlation with population density. Searching marine metagenomes for sequences homologous to an AHL lactonase from the phosphotriesterase-like lactonase (PLL) family, we identified new putative AHL lactonases (sharing 30 to 40% amino acid identity to a thermostable PLL member). Phylogenetic analysis indicated that these putative AHL lactonases comprise a new clade of marine enzymes in the PLL family. Following recombinant expression and purification, we verified the AHL lactonase activity for one of these proteins, named moLRP (marine-originated lactonase-related protein). This enzyme presented greater activity and stability at a broad range of temperatures and pH, tolerance to high salinity levels (up to 5 M NaCl), and higher durability in bacterial culture, compared to another PLL member, parathion hydrolase (PPH). The addition of purified moLRP to cultures of Pseudomonas fluorescens inhibited its extracellular protease activity, expression of the protease encoding gene, biofilm formation, and the sedimentation process in milk-based medium. These findings suggest that moLRP is adapted to the marine environment and can potentially serve as an effective QQ enzyme, inhibiting the QS process in Gram-negative bacteria involved in food spoilage. IMPORTANCE Our results emphasize the potential of sequence and structure-based identification of new QQ enzymes from environmental metagenomes, such as from the ocean, with improved stability or activity. The findings also suggest that purified QQ enzymes can present new strategies against food spoilage, in addition to their recognized involvement in inhibiting bacterial pathogen virulence factors. Future studies on the delivery and safety of enzymatic QQ strategy against bacterial food spoilage should be performed.


Assuntos
Pseudomonas fluorescens , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Metagenoma , Filogenia , Pseudomonas/genética , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/metabolismo , Percepção de Quorum
19.
Crit Rev Food Sci Nutr ; 62(15): 4242-4265, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33480260

RESUMO

A large portion of global food waste is caused by microbial spoilage. The modern approach to preserve food is to apply different hurdles for microbial pathogens to overcome. These vary from thermal processes and chemical additives, to the application of irradiation and modified atmosphere packaging. Even though such preservative techniques exist, loss of food to spoilage still prevails. Plant compounds and peptides represent an untapped source of potential novel natural food preservatives. Of these, antimicrobial peptides (AMPs) are very promising for exploitation. AMPs are a significant component of a plant's innate defense system. Numerous studies have demonstrated the potential application of these AMPs; however, more studies, particularly in the area of food preservation are warranted. This review examines the literature on the application of AMPs and other plant compounds for the purpose of reducing food losses and waste (including crop protection). A focus is placed on the plant defensins, their natural extraction and synthetic production, and their safety and application in food preservation. In addition, current challenges and impediments to their full exploitation are discussed.


Assuntos
Peptídeos Antimicrobianos , Eliminação de Resíduos , Alimentos , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Plantas
20.
Molecules ; 27(6)2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35335268

RESUMO

Food spoilage makes foods undesirable and unacceptable for human use. The preservation of food is essential for human survival, and different techniques were initially used to limit the growth of spoiling microbes, e.g., drying, heating, salting, or fermentation. Water activity, temperature, redox potential, preservatives, and competitive microorganisms are the most important approaches used in the preservation of food products. Preservative agents are generally classified into antimicrobial, antioxidant, and anti-browning agents. On the other hand, artificial preservatives (sorbate, sulfite, or nitrite) may cause serious health hazards such as hypersensitivity, asthma, neurological damage, hyperactivity, and cancer. Thus, consumers prefer natural food preservatives to synthetic ones, as they are considered safer. Polyphenols have potential uses as biopreservatives in the food industry, because their antimicrobial and antioxidant activities can increase the storage life of food products. The antioxidant capacity of polyphenols is mainly due to the inhibition of free radical formation. Moreover, the antimicrobial activity of plants and herbs is mainly attributed to the presence of phenolic compounds. Thus, incorporation of botanical extracts rich in polyphenols in perishable foods can be considered since no pure polyphenolic compounds are authorized as food preservatives. However, individual polyphenols can be screened in this regard. In conclusion, this review highlights the use of phenolic compounds or botanical extracts rich in polyphenols as preservative agents with special reference to meat and dairy products.


Assuntos
Conservantes de Alimentos , Polifenóis , Antioxidantes/farmacologia , Laticínios , Conservantes de Alimentos/farmacologia , Humanos , Carne , Polifenóis/farmacologia
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