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Copper (Cu) toxicity is a pressing concern for several soils, especially in organic viticulture. The objective of this work was to assess Cu toxicity on the non-target organism Eisenia fetida, employing both traditional and novel tools for early identi- fication of Cu-induced damages. In addition to traditional tests like avoidance and reproductive toxicity experiments, other tests such as the single cell gel electrophoresis (SCGE) and gut microbiome analysis were evaluated to identify early and more sensitive pollution biomarkers. Four sub-lethal Cu concentrations were studied, and the results showed strong dose- dependent responses by the earthworm avoidance test and the exceeding of habitat threshold limit at the higher Cu doses. An inverse proportionality was observed between reproductive output and soil Cu concentration. Bioaccumulation was not detected in earthworms; soil concentrations of potentially bioavailable Cu were not affected by E. fetida presence or by time. On the contrary, the SCGE test revealed dose-dependent genotoxicity for the ‘tail length’ parameter already at the second day of Cu exposition. Gut microbiome analysis a modulation of microbial composition, with the most aboundant families being Pectobateriaceae, Comamonadaceae and Microscillaceae. Bacillaceae increased over time and showed adaptability to copper up to 165 mg/kg, while at the highest dose even the sensitive Acetobacteriaceae family was affected. The research provided new insights into the ecotoxicity of Cu sub-lethal doses highlighting both alterations at earthworms’ cellular level and changes in their gut microbiota.

The administration of goat milk fermented (FGM) with Lactobacillus delbrueckii subsp. indicus CRL1447 and supplemented with different mixes of lactobacilli strains (Mix1: Limosilactobacillus fermentum CRL1446 + Lactiplantibacillus paraplantarum CRL1449 + Lactiplantibacillus paraplantarum CRL1472; Mix2: CRL1446 + CRL1449; Mix3: CRL1446 + CRL1472; and Mix4: CRL1449 + CRL1472) was investigated regarding body weight, metabolic and inflammatory parameters, and gut microbiota (GM) composition in mice fed a high-fat diet (HFD). Body weight gain, adipocyte size, fasting blood glucose, serum triglyceride, and leptin levels were significantly reduced in the group fed FGM+Mix3 compared with the obese mice fed FGM. FGM+Mix2 and FGM+Mix3 modified the GM composition, reversing the dysbiosis caused by the HFD. Although there were no significant changes at the phylum level, the GM composition was significantly changed at the family and genus levels. Results suggest that the administration of FGM+Mix3 improves metabolic and immune profiles in obese mice while positively modulating the GM, therefore attenuating the risk factors associated with obesity.

The food enzyme bacillolysin (EC 3.4.24.28) is produced with the non-genetically modified Bacillus amyloliquefaciens strain HPN 131 by ENMEX SA de CV. The production strain qualifies for the qualified presumption of safety (QPS) approach to safety assessment. The food enzyme under assessment is intended to be used in seven food manufacturing processes: processing of cereals and other grains for the production of baked products, brewed products and distilled alcohol; processing of dairy products for the production of modified milk proteins; processing of meat and fish products for the production of protein hydrolysates; processing of plant- and fungal-derived products for the production of protein hydrolysates; processing of yeasts and yeast products. Since residual amounts of total organic solids (TOS) are not carried over to distilled alcohol, a dietary exposure was estimated only for the remaining six food manufacturing processes. Exposure was estimated to be up to 8.302 mg TOS/kg body weight (bw) per day in European populations. As the production strain qualifies for the QPS status and no issue of concern arose from the production process of the food enzyme, the Panel considered that no toxicological studies other than the assessment of allergenicity were necessary. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no matches were found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded (except for distilled alcohol production), but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use. © 2023 European Food Safety Authority. EFSA Journal published by Wiley-VCH GmbH on behalf of European Food Safety Authority.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) is produced with the non-genetically modified yeast Limtongozyma cylindracea strain MS-5-OF by Meito Sangyo Co., Ltd. The food enzyme is free from viable cells of the production organism. It is intended to be used in five food manufacturing processes: brewing processes, baking processes, milk processing for cheese production, production of free fatty acids by hydrolysis and production of flavouring preparations from dairy products. Dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 1.033 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2,084 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, results in a margin of exposure of at least 2,017. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that a risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

The qualified presumption of safety (QPS) provides a generic pre-assessment of the safety of microorganisms intended for use in the food or feed chains, to support the work of EFSA's Scientific Panels. QPS assessment allows a fast track evaluation of strains belonging to QPS taxonomic units (TUs): species for bacteria, yeast, fungi, protists/microalgae and families for viruses. QPS TUs are assessed for their body of knowledge and safety. Safety concerns related to a QPS TU are reflected, when possible, as ‘qualifications’, which should be tested at strain and/or product level. Based on the possession of potentially harmful traits by some strains, filamentous fungi, bacteriophages, oomycetes, streptomycetes, Enterococcus faecium, Escherichia coli and Clostridium butyricum are excluded from the QPS assessment. Between October 2019 and September 2022, 323 notifications of TUs were received, 217 related to feed additives, 54 to food enzymes, food additives and flavourings, 14 to plant protection products and 38 to novel foods. The list of QPS-recommended TUs is reviewed every 6 months following an extensive literature search strategy. Only sporadic infections with a few QPS status TUs in immunosuppressed individuals were identified and the assessment did not change the QPS status of these TUs. The QPS list has been updated in relation to the most recent taxonomic insights and the qualifications were revised and streamlined. The qualification ‘absence of aminoglycoside production ability’ was withdrawn for Bacillus velezensis. Six new TUs received the QPS status: Bacillus paralicheniformis with the qualification ‘absence of toxigenic activity’ and ‘absence of bacitracin production ability’; Bacillus circulans with the qualifications for ‘production purposes only’ and ‘absence of cytotoxic activity’; Haematococcus lacustris (synonym Haematococcus pluvialis) and Ogataea polymorpha, both with the qualification ‘for production purposes only’; Lactiplantibacillus argento

Cocoa bean fermentation is carried out in different production areas following various methods. This study aimed to assess how the bacterial and fungal communities were affected by box, ground or jute fermentation methods, using high-throughput sequencing (HTS) of phylogenetic amplicons. Moreover, an evaluation of the preferable fermentation method was carried out based on the microbial dynamics observed. Box fermentation resulted in higher bacterial species diversity, while beans processed on the ground had a wider fungal community. Lactobacillus fermentum and Pichia kudriavzevii were observed in all three fermentation methods studied. Moreover, Acetobacter tropicalis dominated box fermentation and Pseudomonas fluorescens abounded in ground-fermented samples. Hanseniaspora opuntiae was the most important yeast in jute and box, while Saccharomyces cerevisiae prevailed in the box and ground fermentation. PICRUST analysis was performed to identify potential interesting pathways. In conclusion, there were noticeable differences between the three different fermentation methods. Due to its limited microbial diversity and the presence of microorganisms that guarantee good fermentation, the box method was found to be preferable. Moreover, the present study allowed us to thoroughly explore the microbiota of differently treated cocoa beans and to better understand the technological processes useful to obtain a standardized end-product.

The food enzyme lysozyme (peptidoglycan N-acetylmuramoylhydrolase; EC 3.2.1.17) is produced with hens' eggs and submitted by DSM Food Specialties BV. It is intended to be used in brewing processes, milk processing for cheese production as well as wine and vinegar production. The dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 4.9 mg TOS/kg body weight per day. This exposure is lower than the intake of the corresponding fraction from eggs, for all population groups. Egg lysozyme is a known food allergen. The Panel considered that, under the intended conditions of use, the residual amounts of lysozyme in treated beers, cheese and cheese products as well as wine and wine vinegar may trigger adverse allergenic reactions in susceptible individuals. Based on the data provided, the origin of the food enzyme and an exposure to the food enzyme comparable to the intake from eggs, the Panel concluded that the food enzyme lysozyme does not give rise to safety concerns under the intended conditions of use, except for the known adverse allergic reactions that occur in susceptible individuals.

The qualified presumption of safety (QPS) approach was developed to provide a regularly updated generic pre-evaluation of the safety of microorganisms intended for use in the food or feed chains. Safety concerns identified for a taxonomic unit (TU) are, where possible, confirmed at the species/strain or product level and reflected by ‘qualifications’ which should be assessed at strain and/or product level by EFSA's Scientific Panels. The generic qualification ‘the strains should not harbour any acquired antimicrobial resistance (AMR) genes to clinically relevant antimicrobials’ applies to all QPS bacterial TUs. The different EFSA risk assessment areas use the same approach to assess the qualification related to AMR genes. In this statement, the terms ‘intrinsic’ and ‘acquired’ AMR genes were defined for the purpose of EFSA's risk assessments, and they apply to bacteria used in the food and feed chains. A bioinformatic approach is proposed for demonstrating the ‘intrinsic’/’acquired’ nature of an AMR gene. All AMR genes that confer resistance towards ‘critically important’, ‘highly important’ and ‘important’ antimicrobials, as defined by the World Health Organisation (WHO), found as hits, need to be considered as hazards (for humans, animals and environment) and need further assessment. Genes identified as responsible for ‘intrinsic’ resistance could be considered as being of no concern in the frame of the EFSA risk assessment. ‘Acquired’ AMR genes resulting in a resistant phenotype should be considered as a concern. If the presence of the ‘acquired’ AMR gene is not leading to phenotypic resistance, further case-by-case assessment is necessary.

Milk and dairy products can be affected by a series of chemical modifications induced by non-enzymatic browning and discoloration phenomena. In food science, non-enzymatic browning is also known as Maillard reaction and generates several classes of metabolites, potentially affecting the product's final quality. On the other hand, a pink/brown discoloration results in the potential rejection of a dairy product with a consequential economic loss to producers. Therefore, in this mini-review, we provide a comprehensive understanding of non-enzymatic browning and discoloration occurring in dairy products, by focusing on the broad spectrum of browning-associated metabolites. Within this scenario, omics approaches based on metabolomics and proteomics technologies become essential to provide more insights of the occurring chemical modifications. In addition, the potential researches in the future are also discussed. An updated and concise overview of the most recent metabolomics and proteomics-based findings evaluating the non-enzymatic browning and pink discoloration of dairy products was carried out, providing also constructive insights and inspiration for future studies on cheese browning.

The qualified presumption of safety (QPS) approach was developed to provide a regularly updated generic pre-evaluation of the safety of microorganisms, intended for use in the food or feed chains, to support the work of EFSA's Scientific Panels. The QPS approach is based on an assessment of published data for each agent, with respect to its taxonomic identity, the body of relevant knowledge and safety concerns. Safety concerns identified for a taxonomic unit (TU) are, where possible, confirmed at the species/strain or product level and reflected by ‘qualifications’. In the period covered by this Statement, no new information was found that would change the status of previously recommended QPS TUs. Of 38 microorganisms notified to EFSA between October 2022 and March 2023 (inclusive) (28 as feed additives, 5 as food enzymes, food additives and flavourings, 5 as novel foods), 34 were not evaluated because: 8 were filamentous fungi, 4 were Enterococcus faecium and 2 were Escherichia coli (taxonomic units that are excluded from the QPS evaluation) and 20 were taxonomic units (TUs) that already have a QPS status. Three of the other four TUs notified within this period were evaluated for the first time for a possible QPS status: Anaerobutyricum soehngenii, Stutzerimonas stutzeri (former Pseudomonas stutzeri) and Nannochloropsis oculata. Microorganism strain DSM 11798 has also been notified in 2015 and as its taxonomic unit is notified as a strain not a species, it is not suitable for the QPS approach. A. soehngenii and N. oculata are not recommended for the QPS status due to a limited body of knowledge of its use in the food and feed chains. S. stutzeri is not recommended for inclusion in the QPS list based on safety concerns and limited information about the exposure of animals and humans through the food and feed chains.

The qualified presumption of safety (QPS) approach was developed to provide a regularly updated generic pre-evaluation of the safety of microorganisms, intended for use in the food or feed chains, to support the work of EFSA's Scientific Panels. The QPS approach is based on an assessment of published data for each agent, with respect to its taxonomic identity, the body of relevant knowledge and safety concerns. Safety concerns identified for a taxonomic unit (TU) are, where possible, confirmed at the species/strain or product level and reflected by ‘qualifications’. In the period covered by this Statement, new information was found leading to the withdrawal of the qualification ‘absence of aminoglycoside production ability’ for Bacillus velezensis. The qualification for Bacillus paralicheniformis was changed to ‘absence of bacitracin production ability’. For the other TUs, no new information was found that would change the status of previously recommended QPS TUs. Of 52 microorganisms notified to EFSA between April and September 2022 (inclusive), 48 were not evaluated because: 7 were filamentous fungi, 3 were Enterococcus faecium, 2 were Escherichia coli, 1 was Streptomyces spp., and 35 were taxonomic units (TUs) that already have a QPS status. The other four TUs notified within this period, and one notified previously as a different species, which was recently reclassified, were evaluated for the first time for a possible QPS status: Xanthobacter spp. could not be assessed because it was not identified to the species level; Geobacillus thermodenitrificans is recommended for QPS status with the qualification ‘absence of toxigenic activity’. Streptoccus oralis is not recommended for QPS status. Ogataea polymorpha is proposed for QPS status with the qualification ‘for production purposes only’. Lactiplantibacillus argentoratensis (new species) is included in the QPS list.

In line with the growing demand for green alternatives to conventional petroleum-derived plastic packaging, fully bio-based and biodegradable biocomposites were developed for this work, for the purpose of packaging dry foods, following the principles of circular economy. Solutions of plasticized chitosan (pCS) were blended with varying amounts of hydrolyzed orange peel (hOP) waste to produce films by casting. The hydrolytic pretreatment of orange peels enabled the creation of biocomposites containing up to 80 wt% hOP, while the formulation with 70 wt% hOP had the best general performance. Chemical characterization of the developed films revealed that chitosan molecules interact electrostatically with pectin molecules in hOP. The strong interaction between chitosan and pectin molecules results in improved mechanical, barrier, and thermal properties of the composite materials compared to their individual components. In addition, the biocomposites exhibit improved water resistance due to their reduced water solubility compared to chitosan and hOP films. The migration of the films’ components in the food simulant Tenax was evaluated, and the results revealed low values, compliant with the current EU regulation. However, due to the electrostatic interactions, the films lost the antimicrobial activity of the individual components, chitosan and hOP, against E. coli and S. aureus bacteria, a property that could turn the developed films into active packaging. Finally, the optical and antioxidant properties and the biodegradability in soil of the developed films were also assayed, showing high transparency, antioxidant capacity, and fast biodegradability, reaching 62.9% weight loss after 26 days of the experiment.

The past decade witnessed the emergence in Shiga toxin-producing Escherichia coli (STEC) infections linked to the consumption of unpasteurized milk and raw milk cheese. The virulence of STEC is primarily attributed to the presence of Shiga toxin genes (stx1 and stx2) carried by Stx-converting bacteriophages, along with the intimin gene eae. Most of the available information pertains to the "Top 7" serotypes associated with STEC infections. The objectives of this study were to characterize and investigate the pathogenicity potential of E. coli UC4224, a STEC O174:H2 strain isolated from semi-hard raw milk cheese and to develop surrogate strains with reduced virulence for use in food-related studies. Complete genome sequence analysis of E. coli UC4224 unveiled the presence of a Stx1a bacteriophage, a Stx2a bacteriophage, the Locus of Adhesion and Autoaggregation (LAA) pathogenicity island, plasmid-encoded virulence genes, and other colonization facilitators. In the Galleria mellonella animal model, E. coli UC4224 demonstrated high pathogenicity potential with an LD50 of 6 CFU/10 & mu;L. Upon engineering E. coli UC4224 to generate single and double mutant derivatives by inactivating stx1a and/or stx2a genes, the LD50 increased by approximately 1 Log-dose in the single mutants and 2 Log-doses in the double mutants. However, infectivity was not completely abolished, suggesting the involvement of other virulence factors contributing to the pathogenicity of STEC O174:H2. Considering the possibility of raw milk cheese serving as a reservoir for STEC, cheesemaking model was developed to evaluate the survival of UC4224 and the adequacy of the respective mutants as reduced-virulence surrogates. All tested strains exhibited the ability to survive the curd cooking step at 48 & DEG;C and multiplied (3.4 Log CFU) in cheese within the subsequent 24 h. These findings indicate that genomic engineering did not exert any unintended effect on the double stx1-stx2 mutant behaviou

Plant growth-promoting rhizobacteria (PGPR) with antagonistic activity toward plant pathogenic fungi are valuable candidates for the development of novel plant protection products based on biocontrol activity. The very first step in the formulation of such products is to screen the potential effectiveness of the selected microorganism(s). In this study, non-pathogenic rhizobacteria were isolated from the rhizosphere of tomato plants and evaluated for their biocontrol activity against three species of mycotoxin-producing Alternaria. The assessment of their biocontrol potential involved investigating both fungal biomass and Alternaria toxin reduction. A ranking system developed allowed for the identification of the 12 best-performing strains among the initial 85 isolates. Several rhizobacteria showed a significant reduction in fungal biomass (up to 76%) and/or mycotoxin production (up to 99.7%). Moreover, the same isolates also demonstrated plant growth-promoting (PGP) traits such as siderophore or IAA production, inorganic phosphate solubilization, and nitrogen fixation, confirming the multifaceted properties of PGPRs. Bacillus species, particularly B. amyloliquefaciens and two strains of B. subtilis, showed the highest efficacy in reducing fungal biomass and were also effective in lowering mycotoxin production. Isolates such as Enterobacter ludwigii, Enterobacter asburiae, Serratia nematodiphila, Pantoea agglomerans, and Kosakonia cowanii showed moderate efficacy. Results suggest that by leveraging the diverse capabilities of different microbial strains, a consortium-based approach would provide a broader spectrum of effectiveness, thereby signaling a more encouraging resolution for sustainable agriculture and addressing the multifaceted nature of crop-related biotic challenges.

Fermented foods have been consumed for more than 10 000 years, making food fermentation probably one of the oldest food technologies implemented by man. Presently, fermented food products are estimated to represent a third of our food intake. The scientific knowledge behind its role and mechanisms of action have only been studied in the past 150 years. Food microbiology has provided many answers behind the roles, modes of action, nutrition, and health effects of fermented foods. Nevertheless, one of the major topics of concern remains the safety demonstration of microbial food cultures. Despite this very long history of traditional use, what is considered fermented in a part of the world is considered spoiled, if not unsafe, in another one. As an example, in late 2017, China blocked the importation of cheeses from Europe due to the presence of microbial food cultures not present in the Chinese 2010 positive list: Penicillium roquefortii, Penicillium camemberti, and the presence in their genomes of mycotoxin genes. This is not unheard of per se, as the Biohazard Panel of the European Food Safety Authority has excluded filamentous fungi from the Qualified Presumption of Safety. The United States (GRAS!– Generally Recognized as Safe) also has a respective procedure in place for the microbial risk assessment of microbial species voluntarily added to the food chain. The International Dairy Federation (IDF), in collaboration with the European Food and Feed Cultures Association, has been working for the past 20 years on an inventory of microbial species with technological properties in fermented foods. Safety demonstration of food and feed cultures through inoculation into a food matrix for use in the food chain is aimed to avoid trade barriers between countries when a history of safe use cannot be established for an indigenous fermented food product on the international market. It is as well important to avoid the pitfalls of cross- over fermentation, when changing the tr

The application of microbial biostimulants to plants has revealed positive effects related to nutrients uptake, stress tolerance, root development and phenological growth. However, little information is available exploiting the potential synergistic biostimulant action of microbes on the functional quality of the yields. The current research elucidated the effect of single or coupled action of biostimulants, associated with either optimal or reduced nitrogen application, on the functional quality of tomato fruits. Chemical assays and untargeted metabolomics were applied to investigate Rhizoglomus irregulare and Funneliformis mosseae administration (both being arbuscular mycorrhiza, AMF), under optimal or low N input conditions, alone or coupled to Trichoderma atroviride application. The coupling of AMF and Trichoderma fungal inoculations resulted in a synergistic biostimulant effect on tomato fruits under sub-optimal fertility, revealing improved concentrations of carotenoid compounds-B-carotene (0.647 +/- 0.243 mg/100 g), Z-carotene (0.021 +/- 0.021 mg/100 g), 13-z-lycopene (0.145 +/- 0.052 mg/100 g) and all-trans-lycopene (12.586 +/- 1.511 mg/100 g), and increased values for total phenolic content (12.9 +/- 2.9 mgGAE/g), total antioxidant activity (phosphomolybdenum, 0.9 +/- 0.2 mmolTE/g), radical scavenging activity (DPPH, 3.4 +/- 3.7 mgTE/g), reducing power (FRAP, 23.6 +/- 6.3 mgTE/g and CUPRAC, 37.4 +/- 7.6 mg TE/g), and enzyme inhibitory activity (AChE, 2.4 +/- 0.1 mg GALAE/g), when compared to control. However, evidence of carotenoid and bioactive compounds were exclusively observed under the sub-optimal fertility and no significant differences could be observed between the biostimulant treatment and control under optimal fertility.

Introduction: Poor quality silage can derive from the presence of deleterious microorganisms such as clostridia. Their dissemination along the food chain, especially in milk, causes issues such as the cheese late-blowing defect, particularly triggered by Clostridium tyrobutyricum. The scope of our study was to determine the C. tyrobutyricum occurrence in three different farms across four time periods in relation to the animal diets, specifically the Total Mixed Ration (TMR), by using real-time PCR. Methods: For this purpose, molecular-derived data were exploited to optimize a predictive model that simulated the farm conditions favoring the growth of butyric acid bacteria such as C. tyrobutyricum. Results: Our results showed that the originally utilized predictive model strongly underestimated the growth of C. tyrobutyricum in comparison to the molecular data. At the same time, our findings uncovered an additional source of contamination in the TMR related to silage and dietary residues that represent a reservoir of microbial contamination during successive TMR preparation. Based on these findings, the optimization of the model parameters such as growth rate range and the inclusion of the residues in the model, allowed a more accurate prediction of the contamination levels. Therefore, this study revealed that proper hygiene practices such as the removal of silage and TMR residues within the farm environment is essential to control the contamination by C. tyrobutyricum and avoid food waste and economic losses.

A multi-omics approach was adopted to investigate the impact of lactic acid fermentation and seed germination on the composition and physicochemical properties of rye doughs. Doughs were prepared with either native or germinated rye flour and fermented with Saccharomyces cerevisiae, combined or not with a sourdough starter including Limosilactobacillus fermentum, Weissella confusa and Weissella cibaria. LAB fermentation significantly increased total titrable acidity and dough rise regardless of the flour used. Targeted metagenomics revealed a strong impact of germination on the bacterial community profile of sprouted rye flour. Doughs made with germinated rye displayed higher levels of Latilactobacillus curvatus, while native rye doughs were associated with higher proportions of Lactoplantibacillus plantarum. The oligosaccharide profile of rye doughs indicated a lower carbohydrate content in native doughs as compared to the sprouted counterparts. Mixed fermentation promoted a consistent decrease in both monosaccharides and low-polymerization degree (PD)-oligosaccharides, but not in high-PD carbohydrates. Untargeted metabolomic analysis showed that native and germinated rye doughs differed in the relative abundance of phenolic compounds, terpenoids, and phospholipids. Sourdough fermentation promoted the accumulation of terpenoids, phenolic compounds and proteinogenic and non-proteinogenic amino acids. Present findings offer an integrated perspective on rye dough as a multi-constituent system and on cereal-sourced bioactive compounds potentially affecting the functional properties of derived food products.

Metallic nanoparticles (MNPs) are becoming widespread environmental contaminants. They are currently added to several food preparations and cause a fast-growing concern for human health. The present work aims to assess the impact of zinc oxide (ZnO), titanium dioxide (TiO2), and silver (Ag) nanoparticles (NPs) on the human gut metabolome and microbiome. Water samples spiked with two different concentrations of each MNPs were subjected to in-vitro gastrointestinal digestion and in-vitro large intestine fermentation. The effects of the treatments were determined through 16 S amplicon sequencing and untargeted metabolomics. Multi-omics data integration was then applied to correlate the two datasets. MNPs treatments modulated the microbial genera Bifidobacterium, Sutterella, Escherichia and Bacteroides. The treatments, especially the lower concentrations of Ag and ZnO, caused modulation of indole derivatives, peptides, and metabolites related to protein metabolism in the large intestine. Notably, these metabolites are implicated in ulcerative colitis and inflammatory bowel disease. TiO2 NPs treatment in all concentrations increased E.coli relative abundance and decreased the abundance of B. longum. Moreover, for TiO2, an enrichment in proinflammatory lipid mediators of arachidonic acid metabo-lites, such as prostaglandin E2 and leukotrienes B4, was detected. For all metals except TiO2, low NP concen-trations promoted differentiated profiles, thus suggesting that MNPs aggregation can limit adverse effects on living cells.

Buttafuoco dell’Oltrepo’ Pavese (or Buttafuoco) is an important and renowned red wine, protected by a Denominazione di Origine Controllata (DOC) designation established in 2010, produced in the Northern Italy in the province of Pavia (Italy). The knowledge of factors as the typical microbial terroir and the metabolite composition of the wine is fundamental for producing excellent wines. In this work, two productions of Buttafuoco Storico dell’Oltrep`o Pavese were followed in order to assess the microbial populations through different stages of the wine production chain and the metabolomic composition of the final wines. Microbial terroir was investigated through a metagenomic analysis that revealed a wide microbial consortium which is, for the major taxonomic groups, affected by sampling time over location. Before the metagenomic analysis, being DNA extraction from wine a difficult task, two different approaches were compared for a precise quantification of microbial DNA (bacteria and yeast): digital and real time PCR. Obtained results clearly evidenced that digital PCR being was more sensitive than real time PCR and likely the method of choice for quantifying DNA extracted from processed matrices. Metabolomic profiling, focused on phenolic compounds, was able to clearly distinguish among vineyards and to highlight the presence of discriminating molecules that can be related to the different edaphic conditions.

Natural whey starter cultures are undefined microbial communities mainly consisting of thermophilic lactic acid bacteria (LAB). The technological pressure that shapes the natural whey starter community before and during the back-slopping procedure can impact the amount and viability of the different thermophilic LAB. Traditional culture-dependent analytical methods are useful for evaluating natural whey cultures based on plate enumeration with various culture media and are commonly used as self-control procedures in dairy items. These methods have high variability and require days to obtain results. As the dairy industry has been searching for a solution to this problem for a long time, researchers must explore alternative methods for the technological evaluation of natural whey and assessment of the health status of the thermophilic acidifying bacteria community in the cheesemaking process. The flow cytometry approach has been considered an alternative to classical methods in this work sector. This study compared bacterial enumeration by plate counting and flow cytometry on natural whey samples. Flow cytometry results showed positive agreement with a tendency to overestimate, linearity, and correlation with plate counting. Other parameters have also been introduced for evaluating a natural whey starter, measuring the physiological state of the cells. Specifically, cell-wall damage and metabolic activity were also evaluated, allowing us to quantify the number of cells even in sub-optimal physiological conditions.

Archaeal cell factories are becoming of great interest given their ability to produce a broad range of value-added compounds. Moreover, the Archaea domain often includes extremophilic microorganisms, facilitating their cultivation at the industrial level under nonsterile conditions. Halophilic archaea are studied for their ability to grow in environments with high NaCl concentrations. In this study, nine strains of Halobacterium salinarum were isolated from three different types of salted food, sausage casings, salted codfish, and bacon, and their genomes were sequenced along with the genome of the collection strain CECT 395. A comparative genomic analysis was performed on these newly sequenced genomes and the publicly available ones for a total of 19 H. salinarum strains. We elucidated the presence of unique gene clusters of the species in relation to the different ecological niches of isolation (salted foods, animal hides, and solar saltern sediments). Moreover, genome mining at the single-strain level highlighted the metabolic potential of H. salinarum UC4242, which revealed the presence of different protechnological genes (vitamins and myo-inositol biosynthetic pathways, aroma- and texture-related features, and antimicrobial compounds). Despite the presence of genes of potential concern (e.g., those involved in biogenic amine production), all the food isolates presented archaeocin-related genes (halocin-C8 and sactipeptides).

In this work, the synergistic/antagonistic impact of glucose and mixed starter cultures, namely Latilactobacillus sakei, Pediococcus pentosaceus, and Staphylococcus xylosus, was evaluated in Italian salami in terms of metab-olomics and sensory profiles. As expected, Salami manufactured with 0.5 % glucose exhibited a substantial pH drop, showing values close to 5 at 12 days of ripening. Metabolomics revealed 1841 metabolites, mainly belonging to amino acids, peptides, glycerolipids, and nucleic acids, showing a greater hierarchical role of glucose addition when compared with inoculated microbial starters. Distinct metabolomic fingerprints could be observed across treatments, mainly concerning glutamyl peptides like gamma-glutamyl-glutamate (related to the kokumi taste), biogenic amines (spermine), and lipid oxidation products (i.e., the oxylipin 13S-hydroperoxylino-lenic acid). Such differences may drive the differences in sensory profiles recorded among treatments. These findings indicate the need to select ad-hoc starter cultures to improve the safety, quality, and sensory traits of salami.

This study aims to provide information on the behaviour and biopersistence rate (BP) of metallic nanoparticles (Ag-NPs, TiO2-NPs, ZnO-NPs) naturally occurring in canned seafood and subjected to static in vitro digestion. Single particle ICP-MS analysis was performed to determine NPs distribution and concentrations in oral, gastric, and intestinal digests. Depending on the conditions of the digestive phase and the sample matrix, the phenomena of agglomeration and dispersion were highlighted and confirmed by Dynamic Light Scattering (DLS) technique. In standard suspensions, Ag-NPs had lower biopersistence (BP) than ZnO and TiO2-NPs (BP 34%, 89% and >100%, respectively). Among Ag-NPs and TiO2-NPs naturally present in the food matrix, those in canned tuna were more degradable than those in canned clam (BP Ag-NPs 36% vs. > 100%; BP TiO2-NPs 96% vs. > 100%), while BP ZnO-NPs showed high biopersistence in both seafood matrix (>100%). The biopersistence rates were higher than the recommended limit set by European Food Safety Authority (EFSA) (12%), referred to nanotechnologies to be applied in the food and feed chain, thus the investigated naturally occurring NPs cannot be considered readily degradable.