Piacentinu Ennese PDO cheese as reservoir of promising probiotic bacteria

Piacentinu Ennese is a protected designation of origin (PDO) cheese produced in the surrounding area of Enna (Sicily, Italy), using raw ewe’s milk without the addition of any starter cultures. In the present study, the Lactobacillus population of Piacentinu Ennese PDO cheese was in vitro screened in order to select promising probiotic strains to be further used in humans. One hundred and sixty-nine lactic acid bacteria (LAB) were isolated from 90 days ripened cheeses and identified by Rep-PCR genomic fingerprinting, using the (GTG)5-primer, and by MALDI-TOF MS. One hundred and thirteen (113) isolates belonging to QPS-list species were characterized for both safety and functional properties. All tested isolates were considered safe because none showed either gelatinase, DNase, mucinase, or hemolytic activity. Tolerance to lysozyme, bile salts, and acidic conditions, along with ability to survive under simulated gastrointestinal digestion, were observed. In addition, based on antimicrobial activity against pathogens, cell surface characteristics, Caco-2 adhesion abilities, and anti-inflammatory potential, it was possible to confirm the strain-dependent functional aptitude, suggesting that Piacentinu Ennese PDO cheese may be considered a precious source of probiotic candidates

Biological control of peach fungal pathogens by commercial products and indigenous yeasts.

The potential use of the commercial biocontrol products Serenade (Bacillus subtilis QST-713) and Trichodex (Trichoderma harzianum Rifai strain T39) to inhibit the postharvest pathogenic molds Penicillium crustosum and Mucor circinelloides was investigated. Both products exhibited antagonistic activity in vitro against the pathogens, reducing their growth at different levels. In addition, epiphytic yeasts isolated from peaches were identified as Candida maltosa, Pichia fermentans, and Pichia kluyveri by PCR-restriction fragment length polymorphism of internal transcribed spacer regions and screened for antagonistic activity against the same molds. The efficacy of biocontrol in vitro was dependent on the concentration of the yeast cells. Optimal yeast concentrations were above 10(7) CFU ml(-1). However, C. maltosa and P. fermentans were more effective than P. kluyveri in inhibiting molds. The exclusion of antifungal metabolite production and direct competition for nutrients or space with the pathogens was proposed as the mechanism of biocontrol. Application of biocontrol agents directly on artificially wounded peach fruits significantly reduced the incidence of mold rot during storage at 20 degrees C

Fermentation of Nocellara Etnea table olives by functional starter cultures at different low salt concentrations

Nocellara Etnea is one of the main Sicilian cultivars traditionally used to produce both olive oil and naturally fermented table olives. In the present study, the effect of different salt concentrations on physico-chemical, microbiological, sensorial, and volatile organic compounds (VOCs) formation was evaluated in order to obtain functional Nocellara Etnea table olives. The experimental design consisted of 8 treatments as follow: fermentations at 4, 5, 6, and 8% of salt with (E1-E4 samples) and without (C1-C4 samples) the addition of starters. All the trials were carried out at room temperature (18 ± 2°C) and monitored for an overall period of 120 d. In addition, the persistence of the potential probiotic Lactobacillus paracasei N24 at the end of the process was investigated. Microbiological data revealed the dominance of lactic acid bacteria (LAB), starting from the 7th d of fermentation, and the reduction of yeasts and enterobacteria in the final product inoculated with starters. VOCs profile highlighted a high amount of aldehydes at the beginning of fermentation, which significantly decreased through the process and a concomitant increase of alcohols, acids, esters, and phenols. In particular, esters showed an occurrence percentage higher in experimental samples rather than in control ones, contributing to more pleasant flavors. Moreover, acetic acid, ethanol, and phenols, which often generate off-flavors, were negatively correlated with mesophilic bacteria and LAB. It is interesting to note that salt content did not affect the performances of starter cultures and slightly influenced the metabolome of table olives. Sensory data demonstrated significant differences among samples registering the highest overall acceptability in the experimental sample at 5% of NaCl. The persistence of the L. paracasei N24 strain in experimental samples, at the end of the process, revealed its promising perspectives as starter culture for the production of functional table olives with reduced salt content

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

Profiling of phenol content and microbial community dynamics during pâté olive cake fermentation

In this study, different microbial strains, as single and mixed-cultures, were used to ferment the pâté olive cake (POC), a by-product of olive oil processing. In particular, strains belonging to Candida boidinii, Wickerhamomyces anomalus and Lactiplantibacillus plantarum were used. The fermentation was carried out on diluted (3:2) POC without and with glucose (2% w/v) addition. Furthermore, phenolic compounds were monitored during fermentation in POC added with glucose differetly inoculated and the microbial community, at the end of fermentation, was evaluated by Next Generation Sequencing (NGS) techniques. Data highlighted that inoculated samples showed an hydroxytyrosol content higher than the un-inoculated controls. In particular, during fermentation the sample inoculated with C. boidinii, both in single and in mixed culture together with L. plantarum, increased the hydroxytyrosol content by 275 and 261 mg/L, respectively, after 8 days, to reach the highest content at the end of fermentation. Metagenomic analysis revealed a low abundance of 16S ribosomal RNA genes and fungal ITS in all samples at any sampling times. Furthermore, at the end of fermentation, all samples exhibited a different bacterial community with a decrease in acetic acid bacteria and an increase in Lactobacillaceae biodiversity. Finally, no effect was detected in any samples on fungal metagenomic profile, where Dipodascus geotrichum was found dominant both at initial and final fermentation. In conclusion, the present study confirmed that selected cultures can drive the fermentation and have an impact on the phenolic profile.This study was conducted within a Ph.D. research programme in Biotecnologie (XXXV cycle) by Paola Foti who received a grant ‘Dottorato innovativo con caratterizzazione industriale, PON RI 2014–2020’, titled ‘Olive oil by-products as a new functional food and source of nutritional food ingredients’ from the Department of Agriculture, Food and Environment (Scientific Tutors: C.C. Cinzia Caggia; Flora V. Romeo and Cinzia L. Randazzo). Authors thank the Azienda Olearia Consoli Pasquale & F.lli s.n.c (Adrano, CT), partner of the doctoral programme, to kindly supply the POC. The present study was partially supported by a regional funding Progetto di investimento 144511020025. P.O. FESR SICILIA 2014/2020, 2019–2021, Azione 1.1.3 - Sostegno alla valorizzazione economica dell’innovazione attraverso la sperimentazione e l’adozione di soluzioni innovative nei processi, nei prodotti e nelle formule organizzative, nonch ́e attraverso il finanziamento dell’industrializzazione dei risultati della ricerca: VERIFICO, Project number: 07TP1039000074info:eu-repo/semantics/publishedVersio

Hybridization of saccharomyces cerevisiae sourdough strains with cryotolerant saccharomyces bayanus nbrc1948 as a strategy to increase diversity of strains available for lager beer fermentation

The search for novel brewing strains from non-brewing environments represents an emerging trend to increase genetic and phenotypic diversities in brewing yeast culture collections. Another valuable tool is hybridization, where beneficial traits of individual strains are combined in a single organism. This has been used successfully to create de novo hybrids from parental brewing strains by mimicking natural Saccharomycescerevisiae ale 7 Saccharomyceseubayanus lager yeast hybrids. Here, we integrated both these approaches to create synthetic hybrids for lager fermentation using parental strains from niches other than beer. Using a phenotype-centered strategy, S. cerevisiae sourdough strains and the S. eubayanus 7 Saccharomyces uvarum strain NBRC1948 (also referred to as Saccharomyces bayanus) were chosen for their brewing aptitudes. We demonstrated that, in contrast to S. cerevisiae 7 S. uvarum crosses, hybridization yield was positively affected by time of exposure to starvation, but not by staggered mating. In laboratory-scale fermentation trials at 20 \ub0C, one triple S. cerevisiae 7 S. eubayanus 7 S. uvarum hybrid showed a heterotic phenotype compared with the parents. In 2 L wort fermentation trials at 12 \ub0C, this hybrid inherited the ability to consume efficiently maltotriose from NBRC1948 and, like the sourdough S. cerevisiae parent, produced appreciable levels of the positive aroma compounds 3-methylbutyl acetate (banana/pear), ethyl acetate (general fruit aroma) and ethyl hexanoate (green apple, aniseed, and cherry aroma). Based on these evidences, the phenotype-centered approach appears promising for designing de novo lager beer hybrids and may help to diversify aroma profiles in lager beer

Saccharomyces hybrids as a tool for improving the quality of Moscato di Siracusa DOC wine

The study aimed to evaluate four Saccharomyces cerevisiae strains, one intraspecific S. cerevisiae hybrid, and five interspecific S. cerevisiae×S. uvarum hybrids with respect to the quality of Moscato di Siracusa DOC wine by comparing them with a commercial Saccharomyces cerevisiae strain. Most of the interspecific hybrids maintained volatile acidity (VA) at very low levels, produced high concentrations of glycerol, malic and succinic acid, and yielded the highest concentration of positive sensory attributes. On the basis of the results of these experimental fermentation trials, a real opportunity to produce special wines employing S. cerevisiae×S. uvarum hybrids is proposed.The study aimed to evaluate four Saccharomyces cerevisiae strains, one intraspecific S. cerevisiae hybrid, and five interspecific S. Cerevisiae×S. uvarum hybrids with respect to the quality of Moscato di Siracusa DOC wine by comparing them with a commercial Saccharomyces cerevisiae strain.Most of the interspecific hybrids maintained volatile acidity (VA) at very low levels, producedhigh concentrations of glycerol, malic and succinic acid, and yielded the highest concentrationof positive sensory attributes.On the basis of the results of these experimental fermentation trials, a real opportunity to producespecial wines employing S. cerevisiae×S. uvarum hybrids is proposed

Use of microbial pools for the enhancement of olive pâté by products

La valorizzazione dei sottoprodotti agroalimentari richiede la rispondenza a criteri di economicità ed innovazione che possono includere la progettazione di nuovi prodotti a medio e ad elevato valore aggiunto. In particolare, i sottoprodotti oleari rappresentano una fonte di molecole bioattive, la cui azione benefica è stata riconosciuta dall’EFSA. Recentemente, crescente interesse è rivolto al pâté, sottoprodotto ottenuto dall’estrazione olearia attraverso l’utilizzo del decanter multifase (DMF). Il pâté, caratterizzato da un’elevata umidità, dall’assenza di parti legnose e dalla presenza di composti bioattivi, rappresenta una matrice ideale per la formulazione di nuovi alimenti funzionali. Il presente studio ha avuto lo scopo di valorizzare e stabilizzare il pâté attraverso l’impiego di pool microbici. Fermentazioni guidate sono state allestite ed è stato determinato l’effetto di differenti inoculi microbici sulla cinetica di deamarizzazione. Ceppi appartenenti alle specie Candida boidinii, Wickerhamomyces anomalus e Lactiplantibacillus plantarum sono stati inoculati nel pâté ad una densità finale pari a 107 e 108 UFC/g per i lieviti e per L. plantarum, rispettivamente. Sono state disposte diverse tesi: tre inoculate con le singole culture, due inoculate con i ceppi combinati e una inoculata con la miscela dei tre ceppi. La fermentazione è stata monitorata a differenti tempi, attraverso analisi chimiche e microbiologiche. Inoltre, la cinetica di deamarizzazione della componente fenolica è stata monitorata in HPLC e, a fine fermentazione, la comunità microbica è stata caratterizzata attraverso analisi NGS. La fermentazione si è arrestata dopo 14 giorni, quando il pH ha raggiunto valori di 4.33 e 4.36, nei campioni inoculati con i due lieviti in monocoltura. Le analisi microbiologiche hanno evidenziato una densità cellulare costante dei lieviti, una riduzione della carica mesofila aerobia totale e dei lattobacilli in tutti campioni inoculati. La concentrazione di idrossitirosolo ha presentato una riduzione significativa nei campioni inoculati dopo 2 e 4 giorni, seguita da un incremento dopo 8 e 14 giorni. In particolare, un incremento significativo si è osservato, dopo 8 giorni, nei campioni inculati con C. boidinii in coltura singola, nei campioni inoculati con C. boidinii in associazione con L. plantarum, e nel campione inoculato con W. anomalus in coltura singola, raggiungendo concentrazioni di 275, 261 e 231 mg/L, rispettivamente, confermando una correlazione tra microbiota e processo di deamarizzazione. Le analisi NGS hanno rilevato una diminuzione delle Acetobacteraceae e la dominanza di Saccharomycetes in tutti i campioni. I risultati ottenuti confermano che la valorizzazione microbiologica del pâté può rappresentare una strategia per l'ottenimento di un prodotto funzionale ad alto valore aggiunto.info:eu-repo/semantics/publishedVersio

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