Lacticaseibacillus rhamnosus TOM 22.8 (DSM 33500) is an effective strategy for managing vaginal dysbiosis, rising the lactobacilli population.

AIM: The present study is a single-centre, randomized, controlled clinical trial aimed to evaluate the effectiveness of the probiotic Lacticaseibacillus rhamnosus TOM 22.8 (DSM 33500) strain, orally administrated, to treat vaginal dysbiosis. METHODS AND RESULTS: Overall, 80 women, with signs and symptoms of vaginal dysbiosis, were enrolled and allocated to the treatment group (A, n=60), who took 1 capsule of the probiotic strain for 10 consecutive days, or the non-treatment group (B, n=20), who did not receive any treatment. Clinical (vaginal signs and symptoms; pH of the vaginal fluid; Amsel criteria; Nugent score; Lactobacillary grade) and microbiological examinations were performed at baseline (T0), 10 days (T1), and 30 (T2) days after the oral administration of the probiotic TOM 22.8 strain. The latter resulted in a restoration of the physiological pH, accompanied by remission or attenuation of clinical signs and symptoms as well as the improvement of the quality of life (QoL). Microbiological data revealed a significant reduction of potentially pathogenic bacteria. CONCLUSION: The administration of the L. rhamnosus TOM 22.8 probiotic strain could be proposed as an effective strategy for the treatment of vaginal dysbiosis.

Exploring the Relationship between Ovarian Cancer and Genital Microbiota: A Systematic Review and Meta-Analysis.

Ovarian cancer (OC) remains a significant health challenge globally, with high mortality rates despite advancements in treatment. Emerging research suggests a potential link between OC development and genital dysbiosis, implicating alterations in the microbiome composition as a contributing factor. To investigate this correlation, a meta-analysis was conducted following PRISMA and MOOSE guidelines, involving eight studies encompassing 3504 patients. Studies investigating the role of upper and inferior genital tract dysbiosis were included, with particular reference to HPV infection and/or history of pelvic inflammatory disease. The analysis revealed no significant difference in genital dysbiosis prevalence between OC patients and healthy controls. Although previous literature suggests associations between dysbiosis and gynecologic cancers, such as cervical and endometrial cancers, the findings regarding OC are inconclusive. Methodological variations and environmental factors may contribute to these discrepancies, underscoring the need for standardized methodologies and larger-scale studies. Despite the limitations, understanding the microbiome's role in OC development holds promise for informing preventive and therapeutic strategies. A holistic approach to patient care, incorporating microbiome monitoring and personalized interventions, may offer insights into mitigating OC risk and improving treatment outcomes. Further research with robust methodologies is warranted to elucidate the complex interplay between dysbiosis and OC, potentially paving the way for novel preventive and therapeutic approaches.

Current challenges of microalgae applications: exploiting the potential of non-conventional microalgae species.

The intensified attention to health, the growth of an elderly population, the changing lifestyles, and the medical discoveries have increased demand for natural and nutrient-rich foods, shaping the popularity of microalgae products. Microalgae thanks to their metabolic versatility represent a promising solution for a 'green' economy, exploiting non-arable land, non-potable water, capturing carbon dioxide (CO2) and solar energy. The interest in microalgae is justified by their high content of bioactive molecules, such as amino acids, peptides, proteins, carbohydrates, polysaccharides, polyunsaturated fatty acids (as ω-3 fatty acids), pigments (as ß-carotene, astaxanthin, fucoxanthin, phycocyanin, zeaxanthin and lutein), or mineral elements. Such molecules are of interest for human and animal nutrition, cosmetic and biofuel production, for which microalgae are potential renewable sources. Microalgae, also, represent effective biological systems for treating a variety of wastewaters and can be used as a CO2 mitigation approach, helping to combat greenhouse gases and global warming emergencies. Recently a growing interest has focused on extremophilic microalgae species, which are easier to cultivate axenically and represent good candidates for open pond cultivation. In some cases, the cultivation and/or harvesting systems are still immature, but novel techniques appear as promising solutions to overcome such barriers. This review provides an overview on the actual microalgae cultivation systems and the current state of their biotechnological applications to obtain high value compounds or ingredients. Moreover, potential and future research opportunities for environment, human and animal benefits are pointed out. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of microbial fermentation on functional traits and volatiloma profile of pâté olive cake.

In this study, the pâté olive cake (POC), a by-product of the olive oil industry, was subjected to fermentation in a bioreactor using three microbial strains, Lactiplantibacillus plantarum, Wickerhamomyces anomalus and Candida boidinii, previously isolated from fermented table olive brines. Chemical, microbiological and molecular analyses were carried out at the beginning and at the end of fermentation. The lowest pH value (4.09) was reached after 10 days in sample inoculated with C. boidinii. Microbiological analyses exhibited the dominance of yeasts throughout the whole process (from 5.5 to 7.80 Log10 CFU/g), as confirmed by PCR-DGGE analysis. The microbial cultures affected both phenolic and volatile organic compound profiles. Moreover, the POC samples treated with different microbial strains were investigated for biological assays. The sample fermented with W. anomalus showed the greatest diffusion speed of transepithelial transport through Caco-2 cell, the highest inhibitory activity towards the tested cyclooxygenases and the highest antioxidant activity.

Effect of olive cake supplementation on faecal microbiota profile of Holstein and Modicana dairy cattle.

The present study aimed to investigate the effect of olive cake supplementation on faecal microbiota of Holstein (n = 16) and Modicana (n = 16) dairy cows. Although no difference in richness was detected, within breeds and between the two dietary treatment, the PERMANOVA analysis applied to the beta diversity allowed to discriminate samples according to breeds (p < 0.001) and treatment (p < 0.001). In Holstein cows, the olive cake supplementation led to the increase of Pseudobutyrivibrio and Christensenellaceae_R7-group genera (p < 0.05) recognized as health-promoting or associated with feed efficiency. Differently, no difference was detected between control and treated groups for Modicana suggesting a high adaptive capacity to diet changes. In addition, the higher prevalence of Firmicutes phyla in the Modicana microbiota reflected its better capacity to digest the fibrous sources. Our study supports the suitability of olive cake as a feed supplement for cows and could help validating a sustainable livestock system in the Mediterranean area, characterized by a relevant oil production and by a native breeds reared with extensive systems.

Evaluation of probiotic growth stimulation using prebiotic ingredients to optimize compounds for in ovo delivery.

The use of probiotics, prebiotics and synbiotics in poultry diets beneficially stimulates the gut microbiome thus promoting the health and welfare of the animals. In this study, we analyzed 7 poultry probiotics (Lactobacillus plantarum - B1 and B4, Lactobacillus rhamnosus - B3, Bifidobacterium lactis - B2, Carnobacterium divergens - B5, Propionibacterium thoenii - B6, Clostridium butyricum - B7) and 12 prebiotics, differing in chemical composition and source of origin (fungi, algae, animal, etc.). The main goal of our research was to select the most promising candidates to develop synbiotic combinations. We determined the growth kinetics of all probiotics in the presence of prebiotics in a series of in vitro studies to select optimal combinations. Five out of seven investigated probiotics were significantly stimulated by astragalus polysaccharide, and this prebiotic was characterized in our work as the most effective. Moreover, in the case of three probiotics, B2, B3 and B4, significant growth stimulation has been found when beta-glucan, vegetable protein hydrolysate and liquid seaweed extract were supplied. Strain B1 (L. plantarum) was stimulated by 6 out of 12 prebiotics. The growth of B4 (L. plantarum) and B2 (B. lactis) was enhanced by prebiotics after 2 h of incubation. A high growth rate of 3.13% was observed in the case of L. plantarum (B4) and a 3.37% higher rate for B. lactis (B3), compared to the growth of probiotics in the control medium with glucose but no prebiotics. The best candidates for synbiotic combinations based on this in vitro work are the strains belonging to L. plantarum (B4), L. rhamnosus (B3) and B. lactis (B2), consistent with prebiotics such as astragalus polysaccharides and vegetable protein hydrolysate. These combinations will be subject to future in vivo poultry trials involving the in ovo microbiome modulation.

Anthocyanin Effects on Vascular and Endothelial Health: Evidence from Clinical Trials and Role of Gut Microbiota Metabolites.

Hypertension and derived cardiovascular disease (CVD) are among the leading causes of death worldwide. Increased oxidative stress and inflammatory state are involved in different alterations in endothelial functions that contribute to the onset of CVD. Polyphenols, and in particular anthocyanins, have aroused great interest for their antioxidant effects and their cardioprotective role. However, anthocyanins are rarely detected in blood serum because they are primarily metabolized by the gut microbiota. This review presents studies published to date that report the main results from clinical studies on the cardioprotective effects of anthocyanins and the role of the gut microbiota in the metabolism and bioavailability of anthocyanins and their influence on the composition of the microbiota. Even if it seems that anthocyanins have a significant effect on vascular health, more studies are required to better clarify which molecules and doses show vascular benefits without forgetting the crucial role of the microbiota.

Effects of Dietary Enrichment with Olive Cake on the Thyroid and Adrenocortical Responses in Growing Beef Calves.

Agro-industrial by-products incorporated into livestock feed formulations can positively impact feed costs and promote a circular bio-economy. Italy produces significant amounts of olive cake (OC), a by-product of olive oil extraction, with the potential for incorporation into bovine diets. However, information on its effects on endocrine responses in growing beef calves is lacking. Forty-eight Limousines randomly allocated to dietary treatment (control or 10%-OC or 15%-OC inclusion) were segregated according to sex and body weight. Serum concentrations of TSH, thyroid hormones, and cortisol were measured on day 0, day 56, and at the end of the trial on day 147. Circulating TSH, total (T3, T4) and free (fT3, fT4) iodothyronines, and cortisol concentrations were all within the normal physiological ranges, with no significant effect imparted by diet. However, the diet × time interaction was significant for T3. The cortisol, T3, T4, and fT4 registered on day 147 were higher than those of day 56, and cortisol was higher in heifers than bulls. Final body weight was positively correlated with TSH and T3 and negatively with cortisol concentration. These findings suggest that the inclusion of OC at levels up to 15% in growing/finishing beef diets had no adverse effects on the calves' thyroid and cortical status.

Inside Current Winemaking Challenges: Exploiting the Potential of Conventional and Unconventional Yeasts.

Wine represents a complex matrix in which microbial interactions can strongly impact the quality of the final product. Numerous studies have focused on optimizing microbial approaches for addressing new challenges to enhance quality, typicity, and food safety. However, few studies have investigated yeasts of different genera as resources for obtaining wines with new, specific traits. Currently, based on the continuous changes in consumer demand, yeast selection within conventional Saccharomyces cerevisiae and unconventional non-Saccharomyces yeasts represents a suitable opportunity. Wine fermentation driven by indigenous yeasts, in the various stages, has achieved promising results in producing wines with desired characteristics, such as a reduced content of ethanol, SO2, and toxins, as well as an increased aromatic complexity. Therefore, the increasing interest in organic, biodynamic, natural, or clean wine represents a new challenge for the wine sector. This review aims at exploring the main features of different oenological yeasts to obtain wines reflecting the needs of current consumers in a sustainability context, providing an overview, and pointing out the role of microorganisms as valuable sources and biological approaches to explore potential and future research opportunities.

Effects of the supplementation with a multispecies probiotic on clinical and laboratory recovery of children with newly diagnosed celiac disease: A randomized, placebo-controlled trial.

OBJECTIVE: To evaluate the efficacy of a multispecies probiotic on clinical and laboratory recovery of children with celiac disease (CeD) at diagnosis. METHODS: Children with newly diagnosed CeD entered a randomized double-blind placebo-controlled trial. A gluten-free diet (GFD) plus a multispecies probiotic or placebo were administered for 12 weeks. Growth, laboratory, and clinical parameters were recorded at enrollment, after 3 and 6 months of follow-up. RESULTS: Overall, 96 children completed the study: 49 in group A (placebo) and 47 in group B (probiotic). A significant increase of BMI-Z score was found in both groups after 3 and 6 months of treatment (p < 0.001), however the increase of BMI-Z score was significantly higher and faster in Group B than in Group A. Other clinical and laboratory parameters improved in both groups after 3 and 6 months (p<0.001), but no difference was found between the groups and a comparable time trend was observed in both groups. CONCLUSIONS: Treatment with a multispecies probiotic induced a higher and faster increase of BMI in children with newly diagnosed CeD. The mechanism of this positive effect remains to be elucidated.

Influence of olive cake dietary supplementation on fecal microbiota of dairy cows.

Olive by-products represent a valuable low-price feed supplement for animal nutrition. In the present study, the effect of the dietary destoned olive cake supplementation, on both composition and dynamics of the fecal bacterial biota of cow, was assessed by Illumina MiSeq analysis of the 16S rRNA gene. In addition, metabolic pathways were predicted by using the PICRUSt2 bioinformatic tool. Eighteen lactating cows, according to the body condition score, the days from calving, and the daily milk production were homogeneously allocated into two groups, control or experimental, and subjected to different dietary treatments. In detail, the experimental diet contained, along with the components of the control one, 8% of destoned olive cake. Metagenomics data revealed significant differences in abundance rather than in richness between the two groups. Results showed that Bacteroidota and Firmicutes were identified as the dominant phyla, accounting for over 90% of the total bacterial population. The Desulfobacterota phylum, able to reduce sulfur compounds, was detected only in fecal samples of cows allocated to the experimental diet whereas the Elusimicrobia phylum, a common endosymbiont or ectosymbiont of various flagellated protists, was detected only in cows subjected to the control diet. In addition, both Oscillospiraceae and Ruminococcaceae families were mainly found in the experimental group whereas fecal samples of control cows showed the presence of Rikenellaceae and Bacteroidaceae families, usually associated with the high roughage or low concentrate diet. Based on the PICRUSt2 bioinformatic tool, pathways related to carbohydrate, fatty acid, lipid, and amino acids biosynthesis were mainly up regulated in the experimental group. On the contrary, in the control group, the metabolic pathways detected with the highest occurrence were associated with amino acids biosynthesis and degradation, aromatic compounds degradation, nucleosides and nucleotides biosynthesis. Hence, the present study confirms that the destoned olive cake is a valuable feed supplement able to modulate the fecal microbiota of cows. Further studies will be conducted in order to deepen the inter-relationships between the GIT microbiota and the host.

Technological Characterization of Lactic Acid Bacteria Strains for Potential Use in Cheese Manufacture.

A total of 26 lactic acid bacteria isolates from both Italian and Brazilian cheeses were tested for their use in cheesemaking. Isolates were screened for salt tolerance, exopolysaccharide and diacetyl production, lipolytic, acidifying, and proteolytic activities. In addition, the aminopeptidase (Pep N and Pep X) activities, were evaluated. Most of the strains demonstrated salt tolerance to 6% of NaCl, while only two L. delbruekii (P14, P38), one L. rhamnosus (P50) and one L. plantarum (Q3C4) were able to grow in the presence of 10% (w/v) of NaCl. Except for 2 L. plantarum (Q1C6 and Q3C4), all strains showed low or medium acidifying activity and good proteolytic features. Furthermore, lipolytic activity was revealed in none of the strains, while the production of EPS and diacetyl was widespread and variable among the tested strains. Finally, regarding aminopeptidase activities, 1 L. delbrueckii (P10), 1 L. rhamnosus (P50), and 1 L. lactis (Q5C6) were considered as the better performing, showing high values of both Pep N and Pep X. Based on data presented here, the aforementioned strains could be suggested as promising adjunct cultures in cheesemaking.

Protective Effect of Treated Olive Mill Wastewater on Target Bacteria and Mitochondrial Voltage-Dependent Anion-Selective Channel 1.

Olive mill wastewater, a by-product of the olive oil industry, represents an important resource, rich in bioactive compounds with antioxidant activity. In this study, two strategies to concentrate the bioactive components were used: the tangential membrane filtration (ultrafiltration and reverse osmosis) and the selective resin extraction. The concentrates were evaluated for physico-chemical characteristics and antioxidant activity. Furthermore, the antimicrobial activity and the effect on the mitochondrial voltage-dependent anion selective channel 1 were evaluated. The chemical results highlighted that the highest concentration of hydroxytyrosol (as 7204 mg/L) was revealed in the sample obtained by inverse osmosis while the highest concentration of oleuropein (10005 mg/L) was detected in the sample obtained by resin extraction. The latter sample exhibited the highest antimicrobial effects against Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Both samples exhibited a high impact on the electrophysiological parameters of VDAC1 activity. These results showed that both valorization techniques, which can be reproduced at industrial scale, provided phenolic concentrates with antioxidant and antimicrobial activity useful for different future perspectives.

Effect of olive by-products feed supplementation on physicochemical and microbiological profile of Provola cheese.

Introduction: With the purpose to evaluate the effects of dietary olive cake, a source of bioactive phenolic compounds, as feed supplementation of lactating dairy cows on fatty acid composition, volatile organic compounds, and microbiological profiles of Provola cheese, we performed a two-arm study where control and experimental administered cows derived dairy have been compared. Methods: Our panel of analyses include metabolomics, physicochemical detected variables, culture dependent and independent analyses, and a stringent statistical approach aimful at disclosing only statistically significant results. Results and discussion: Looking at the physicochemical variable's profiles, a higher content of unsaturated fatty acids, polyunsaturated fatty acid, and conjugated linoleic acids as well of proteins were observed in experimental cheese samples, indicating the beneficial effect of dietary supplementation. Furthermore, based on volatilome composition, a clear cluster separation between control and experimental cheeses was obtained, mainly related to terpenes degradation, able of influencing their aroma and taste. Microbiological results showed a decrease of some spoilage related microbial groups in experimental cheeses, probably due to the inhibitory effect exerted by polyphenols compounds, that contrarily did not affect the core taxa of all cheese samples. This paper confirmed the promising utilization of olive by-product in farming practices to obtain more sustainable and safe dairy food products with lower environmental impact, mainly in Sicily and Mediterranean area, where waste disposal poses serious environmental and economic problems.

A Comprehensive Study on Antibiotic Resistance among Coagulase-Negative Staphylococci (CoNS) Strains Isolated from Ready-to-Eat Food Served in Bars and Restaurants.

The present study aimed to characterize and assess the diversity of CoNS strains as potential vectors for the spread of resistance to antimicrobial agents from RTE foods served in bars and restaurants. Eighty-five CoNS strains, obtained from 198 RTE food samples, were investigated. Sixty-seven CoNS isolates (78.8%) were resistant to at least one antibiotic tested, and 37 (43.5%) were multidrug resistant (MDR-CoNS). Moreover, CoNS strains contained genes conferring resistance to antibiotics critically important in medicine, i.e., ß-lactams [mecA (29.4%); blaZ (84.7%)], aminoglycosides [aac(6')-Ie-aph(2″)-Ia (45.9%); aph(2″)-Ic (3.5%)], macrolides, lincosamides and streptogramin B-MLSB [msrA/B (68.2%); ermB (40%) and mphC (4.7%)], tetracyclines [tetK (31.8%); tetM (16.5%) and/or tetL (2.35%)]. We also found the fusB/C/D genes responsible for the acquired low-level fusidic acid resistance (17.6%) and streptogramin resistance determinant vgaA in 30.6% of isolates. In three linezolid resistant strains (2 S. epidermidis and 1 S. warneri), mutation was detected, as demonstrated by L101V and V188I changes in the L3 protein amino acid sequences. The high frequency in RTE food of MDR-CoNS including methicillin-resistant (MR-CoNS) strains constitutes a direct risk to public health as they increase the gene pool from which pathogenic bacteria can pick up resistance traits.

Olive Mill Wastewater Fermented with Microbial Pools as a New Potential Functional Beverage.

Olive mill wastewater (OMWW) represents a by-product but also a source of biologically active compounds, and their recycling is a relevant strategy to recover income and to reduce environmental impact. The objective of the present study was to obtain a new functional beverage with a health-promoting effect starting from OMWW. Fresh OMWW were pre-treated through filtration and/or microfiltration and subjected to fermentation using strains belonging to Lactiplantibacillus plantarum, Candida boidinii and Wickerhamomyces anomalus. During fermentation, phenolic content and hydroxytyrosol were monitored. Moreover, the biological assay of microfiltered fermented OMWW was detected versus tumor cell lines and as anti-inflammatory activity. The results showed that in microfiltered OMWW, fermentation was successfully conducted, with the lowest pH values reached after 21 days. In addition, in all fermented samples, an increase in phenol and organic acid contents was detected. Particularly, in samples fermented with L. plantarum and C. boidinii in single and combined cultures, the concentration of hydroxytyrosol reached values of 925.6, 902.5 and 903.5 mg/L, respectively. Moreover, biological assays highlighted that fermentation determines an increase in the antioxidant and anti-inflammatory activity of OMWW. Lastly, an increment in the active permeability on Caco-2 cell line was also revealed. In conclusion, results of the present study confirmed that the process applied here represents an effective strategy to achieve a new functional beverage.

Lacticaseibacillus rhamnosus CA15 (DSM 33960) as a Candidate Probiotic Strain for Human Health.

Lactobacilli with probiotic properties have emerged as promising tools for both the prevention and treatment of vaginal dysbiosis. The present study aimed to study the in vitro probiotic potential of the Lacticaseibacillus rhamnosus CA15 (DSM 33960) strain isolated from a healthy vaginal ecosystem. The strain was evaluated for both functional (antagonistic activity against pathogens; H2O2, organic acid, and lactic acid production; antioxidant and anti-inflammatory activities; ability to adhere to intestinal mucus and to both CaCo-2 and VK7/E6E7 cell lines; exopolysaccharide production; surface properties; and ability to survive during gastrointestinal transit) and safety (hemolytic, DNase, and gelatinase activities; mucin degradation ability; production of biogenic amines; and resistance to antimicrobials) characteristics. Data revealed that the tested strain was able to antagonize a broad spectrum of vaginal pathogens. In addition, the adhesion capacity to both vaginal and intestinal cell lines, as well as anti-inflammatory and antioxidant activities, was detected. The ability of the Lacticaseibacillus rhamnosus CA15 (DSM 33960) strain to survive under harsh environmental conditions occurring during the gastrointestinal passage suggests its possible oral delivery. Thus, in vitro data highlighted interesting probiotic properties of the CA15 (DSM 33960) strain, which could represent a valuable candidate for in vivo vaginal infections treatment.

Antimicrobial activity of bovine lactoferrin against Gardnerella species clinical isolates.

Gardnerella species play a key role in the development and recurrence of Bacterial Vaginosis (BV), a common imbalance of the vaginal microbiota. Because of the high rates of BV recurrence reported after treatment with standard of care antibiotics, as well as the emergence of antibiotic-resistant BV, the development of alternative treatment approaches is needed. Bovine lactoferrin, a well studied iron-binding glycoprotein with selective antimicrobial activity, may ameliorate vaginal dysbiosis either alone or in combination with antibiotics. The present study evaluated the antimicrobial resistance/susceptibility profile of seventy-one presumptive G. vaginalis clinical isolates to metronidazole and clindamycin. In addition, the in vitro antimicrobial activity of Metrodora Therapeutics bovine Lactoferrin (MTbLF) against the tested clinical isolates, both alone and in combination with metronidazole and clindamycin, was in depth evaluated using defined-iron culture conditions. All 71 presumptive G. vaginalis clinical isolates exhibited resistance to metronidazole, with MIC values greater than 256 µg/ml. Different susceptibility profiles were detected for clindamycin. In detail, the vast majority of the tested strains (45%), exhibiting MIC lower than 2 µg/ml, were considered sensitive; 18 strains (25%) with MIC higher or equal to 8 µg/ml, were classified as resistant, whereas the remaining 21 (30%) were classified as intermediate. MTbLF was tested in culture medium at different concentrations (32, 16, 8, 4, 2, 1, and 0.5 mg/ml) showing ability to inhibit the growth of the tested presumptive G. vaginalis clinical isolates, including those metronidazole-resistant, in a dose-dependent and not in a strain-dependent manner. MTbLF, at concentrations ranging from 32 to 8 mg/ml, exerted a statistically different antimicrobial activity compared with lower concentrations (4, 2, 1, and 0.5 mg/ml). A synergistic effect between MTbLF (8 and 4 mg/ml) and clindamycin was revealed for all the tested strains. When tested in the absence of other sources of iron, MTbLF did not support the growth of the tested presumptive G. vaginalis clinical isolates. Bovine lactoferrin may be a potential candidate to treat Gardnerella species infection.

Insights on the bacterial composition of Parmigiano Reggiano Natural Whey Starter by a culture-dependent and 16S rRNA metabarcoding portrait.

Natural whey starters (NWS) are undefined bacterial communities produced daily from whey of the previous cheese-making round, by application of high temperature. As a result, in any dairy plant, NWS are continuously evolving, undefined mixtures of several strains and/or species of lactic acid bacteria, whose composition and performance strongly depend on the selective pressure acting during incubation. While NWS is critical to assure consistency to cheese-making process, little is known about the composition, functional features, and plant-to-plant fluctuations. Here, we integrated 16S rRNA metabarcoding and culture-dependent methods to profile bacterial communities of 10 NWS sampled in the production area of Parmigiano Reggiano cheese. 16S rRNA metabarcoding analysis revealed two main NWS community types, namely NWS type-H and NWS type-D. Lactobacillus helveticus was more abundant in NWS type-H, whilst Lactobacillus delbrueckii/St. thermophilus in NWS type-D, respectively. Based on the prediction of metagenome functions, NWS type-H samples were enriched in functional pathways related to galactose catabolism and purine metabolism, while NWS type-D in pathways related to aromatic and branched chain amino acid biosynthesis, which are flavor compound precursors. Culture-dependent approaches revealed low cultivability of individual colonies as axenic cultures and high genetic diversity in the pool of cultivable survivors. Co-culturing experiments showed that fermentative performance decreases by reducing the bacterial complexity of inoculum, suggesting that biotic interactions and cross-feeding relationships could take place in NWS communities, assuring phenotypic robustness. Even though our data cannot directly predict these ecological interactions, this study provides the basis for experiments targeted at understanding how selective regime affects composition, bacterial interaction, and fermentative performance in NWS.

Multi-Functional Potential of Lactic Acid Bacteria Strains and Antimicrobial Effects in Minimally Processed Pomegranate (Punica granatum L. cv Jolly Red) Arils.

This study aimed to evaluate the antimicrobial activity of both cells, and cell-free supernatants (CFS) of 7 selected lactic acid bacteria (LAB) strains belonging to Limosilactobacillus fermentum (4 strains), Lacticaseibacillus paracasei (1 strain), Lacticaseibacillus rhamnosus (1 strain), and Enterococcus faecium (1 strain) species, against Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa and Staphylococcus aureus, by both the agar-well diffusion and co-culture methods. In addition, probiotic and safety traits were also detected. Great variability was detected on antimicrobial effects, whereas all tested strains were found sensitive to most of the tested antibiotics, and without any DNase, gelatinase, or hemolytic activity. Moreover, strains showed excellent survival in acidic conditions and exhibited tolerance to pepsin and bile salts. Based on the in vitro results, the CFSs of two selected L. fermentum strains were applied, in a mixed solution, as bio-preservative into minimally processed pomegranate arils, inoculated with a cocktail of L. monocytogenes and E. coli. Samples, packaged in an ordinary atmosphere, were analyzed during refrigerated storage, for up to 12 days, for physicochemical (as weight loss, texture, color, pH, total soluble solids and organic acid content) and for microbiological traits. Results revealed the effectiveness of CFS, up to 12 days, in reducing weight loss and microbial growth, without any significant effect on texture, total soluble solid content and color, found comparable to the acid citric treatment, highlighting the multi-functional potential of selected probiotic strains.