RESUMEN

Pediococcus pentosaceus ST65ACC is a bacteriocinogenic lactic acid bacteria (LAB) isolated from Brazilian artisanal cheese that is capable of inhibiting different food pathogens, mainly Listeria monocytogenes. The production of bacteriocins can be influenced by several growth conditions, such as temperature, pH, and medium composition. This study aimed to evaluate the effect of different culture media on the production of bacteriocins and antimicrobial activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The strains were inoculated alone and in coculture in four different media: BHI broth, MRS broth, meat broth, and reconstituted skim milk (RSM) 10% (w/v). The culture media were then incubated at 37 °C for 96 h, and count analysis, pH measurement, and bacteriocin production were performed at 0, 24, 48, 72 and 96 h. L. monocytogenes was inhibited to nondetectable levels in coculture with P. pentosaceus ST65ACC in MRS broth within 96 h, consistent with the high production of bacteriocin throughout the analysis period (3,200-12,800 AU/mL). However, lower inhibitory activities of P. pentosaceus ST65ACC on L. monocytogenes Scott A were recorded in BHI, RSM, and meat broth, with low or no production of bacteriocins at the analyzed times. The composition of these culture media may have repressed the production and activity of bacteriocins and, consequently, the antagonist activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The results showed that the antimicrobial activity was more effective in MRS broth, presenting greater production of bacteriocins and less variability when compared to the other media analyzed.

Asunto(s)

Bacteriocinas , Medios de Cultivo , Listeria monocytogenes , Pediococcus pentosaceus , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/crecimiento & desarrollo , Medios de Cultivo/química , Bacteriocinas/biosíntesis , Bacteriocinas/farmacología , Bacteriocinas/metabolismo , Pediococcus pentosaceus/metabolismo , Antibiosis , Queso/microbiología , Antibacterianos/farmacología , Concentración de Iones de Hidrógeno , Microbiología de Alimentos , Brasil

RESUMEN

This study isolated and identified autochthonous lactic acid bacteria (LAB) from mandacaru fruit and evaluated their potential probiotic and technological aptitudes in vitro, as well as the protective effects of freeze-dried mandacaru fruit on the most promising LAB isolate during lyophilization and refrigeration storage. Initially, 212 colonies were isolated from mandacaru fruit, and 34 were preliminarily identified as LAB. Thirteen isolates identified by 16S-rRNA sequencing as Pediococcus pentosaceus were negative for DNase, gelatinase, hemolytic, and biogenic amine production. The selected isolates showed proteolytic activity, diacetyl and exopolysaccharide production, and good tolerance to different NaCl concentrations while having low cellular hydrophobicity and antagonistic activity against pathogens. The survival of isolates sharply decreased after 3 h of exposure to pH 2 and had a good tolerance to 1 % bile salt. A principal component analysis selected P. pentosaceus 57 as the most promising isolate based on the examined technological and probiotic-related physiological properties. This isolate was lyophilized with mandacaru fruit and stored under refrigeration for 90 days. P. pentosaceus 57 lyophilized with mandacaru fruit had high viable cell counts (9.69 ± 0.03 log CFU/mL) and >50 % of physiologically active cells at 90 days of refrigeration storage. The results indicate that mandacaru fruit is a source of P. pentosaceus with aptitudes to be explored as potential probiotic and technological characteristics of interest for the food industry, besides being a good candidate for use in lyophilization processes and refrigeration storage of LAB due to its cryoprotective effects.

Asunto(s)

Liofilización , Frutas , Pediococcus pentosaceus , Probióticos , Refrigeración , Pediococcus pentosaceus/metabolismo , Frutas/microbiología , Lactobacillales/metabolismo , Lactobacillales/genética , Lactobacillales/fisiología , Almacenamiento de Alimentos , Microbiología de Alimentos , Conservación de Alimentos/métodos

RESUMEN

Probiotic microorganisms are a promising alternative to antibiotics in preventing and treating bacterial infections. Within the probiotic group, the lactic acid bacteria (LAB)stand out for their health benefits and for being recognized as safe by regulatory agencies. However, these microorganisms are sensitive to various environmental conditions, including the acidic environment of the stomach. Faced with these obstacles, this work aimed to promote the symbiotic microencapsulation of LAB in a composite matrix of alginate and prebiotics to enhance their survival and improve their probiotic activity during gastrointestinal transit. We evaluated the effect of inulin, fructo-oligosaccharides (FOS) and mannan-oligosaccharides (MOS) as prebiotic sources on the growth of Pediococcus pentosaceus LBM34 strain, finding that MOS favored LAB growth and maintenance of microencapsulated cell viability. The symbiotic microparticles were produced using the spray-drying technique with an average size of 10 µm, a smooth surface, and a composition that favored the stabilization of live cells according to the FTIR and the thermal analysis of the material. The best formulation was composed of 1 % of alginate, 10 % MOS and 1 % M10 (% w/v), which presented notable increases in the survival rates of the probiotic strain in both alkaline and acidic conditions. Therefore, this industrially scalable approach to symbiotic LAB microencapsulation can facilitate their growth and colonization within the host. This effort aims to contribute to reducing antibiotic reliance and mitigating the emergence of new zoonotic diseases, which pose significant challenges to public health.

Asunto(s)

Pediococcus pentosaceus , Probióticos , Alginatos , Prebióticos , Oligosacáridos

RESUMEN

Pediococcus pentosaceus ST65ACC was obtained from a Brazilian artisanal cheese (BAC) and characterized as bacteriocinogenic. This strain presented beneficial properties in previous studies, indicating its potential as a probiotic candidate. In this study, we aimed to carry out a genetic characterization based on whole-genome sequencing (WGS), including taxonomy, biotechnological properties, bacteriocin clusters and safety-related genes. WGS was performed using the Illumina MiSeq platform and the genome was annotated with the Prokaryotic Genome Annotation (Prokka). P. pentosaceus ST65ACC taxonomy was investigated and bacteriocin genes clusters were identified by BAGEL4, metabolic pathways were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and safety-related genes were checked. P. pentosaceus ST65ACC had a total draft genome size of 1,933,194 bp with a GC content of 37.00%, and encoded 1950 protein coding sequences (CDSs), 6 rRNA, 55 tRNA, 1 tmRNA and no plasmids were detected. The analysis revealed absence of a CRISPR/Cas system, bacteriocin gene clusters for pediocin PA-1/AcH and penocin-A were identified. Genes related to beneficial properties, such as stress adaptation genes and adhesion genes, were identified. Furthermore, genes related to biogenic amines and virulence-related genes were not detected. Genes related to antibiotic resistance were identified, but not in prophage regions. Based on the obtained results, the beneficial potential of P. pentosaceus ST65ACC was confirmed, allowing its characterization as a potential probiotic candidate.

Asunto(s)

Bacteriocinas , Queso , Animales , Pediococcus pentosaceus/genética , Leche/metabolismo , Bacteriocinas/metabolismo , Genómica , Pediococcus/metabolismo

RESUMEN

AIMS: This study aims to demonstrate the potential of the lactic acid bacteria (LAB) Pediococcus pentosaceus LBM18 against the mycotoxin-producing Alternaria alternata TEF-1A and highlight its application as an effective grain silage inoculant to control mycotoxin contamination. METHODS AND RESULTS: The antifungal properties of Ped. pentosaceus lyophilized (PPL) were assessed by evaluating its effect on A. alternata TEF-1A grown in a corn silage-based medium, which included morphological changes by Scanning Electron Microscopy (SEM) observations, growth rate, conidia production assays, and inhibition of Tenuazonic acid (TeA) production by high-performance liquid chromatography (HPLC-MS/MS) analyses. Furthermore, TeA biosynthesis was monitored for changes at the molecular level by PKS gene expression. The growth and sporulation processes of A. alternata TEF-1A were affected by Ped. pentosaceus LBM18 in a concentration-dependent manner. Moreover, a significant inhibition of TeA production (74.3%) and the transcription level of the PKS gene (42.9%) was observed. CONCLUSIONS: Ped. pentosaceus is one of the promising LAB to be applied as an inoculant for corn silage preservation, aiming to inhibit mycotoxigenic fungi growth and their mycotoxin production. SIGNIFICANCE AND IMPACT OF THE STUDY: Ped. pentosaceus could be used as an inoculant to reduce fungal and mycotoxins contamination in grain silage production.

Asunto(s)

Micotoxinas , Ácido Tenuazónico , Animales , Ácido Tenuazónico/análisis , Pediococcus pentosaceus/metabolismo , Espectrometría de Masas en Tándem , Ganado/metabolismo , Antifúngicos/farmacología , Antifúngicos/metabolismo , Alternaria , Micotoxinas/metabolismo , Ensilaje/microbiología , Zea mays/metabolismo

RESUMEN

Secretions of beneficial intestinal bacteria can inhibit the growth and biofilm formation of a wide range of microorganisms. Curcumin has shown broad spectrum antioxidant, anti-inflammatory, and antimicrobial potential. It is important to evaluate the influence of these secretions with bioactive peptides, in combination with curcumin, to limit growth and inhibit biofilm formation of pathogenic bacteria of importance in aquaculture. In the present study, the supernatants of Lactoccocus lactis NZ9000, Lactobacillus rhamnosus GG and Pediococcus pentosaceus NCDO 990, and curcumin (0,1,10,25 and 50 µM) were used to evaluate their efficacy in growth, inhibition biofilm and membrane permeability of Aeromonas hydrophila CAIM 347 (A. hydrophila). The supernatants of probiotics and curcumin 1,10 and 25 µM exerted similar effects in reducing the growth of A. hydrophila at 12 h of interaction. The supernatants of the probiotics and curcumin 25 and 50 µM exerted similar effects in reducing the biofilm of A. hydrophila. There is a significant increase in the membrane permeability of A. hydrophila in interaction with 50 µM curcumin at two hours of incubation and with the supernatants separately in the same period. Different modes of action of curcumin and bacteriocins separately were demonstrated as effective substitutes for antibiotics in containing A. hydrophila and avoiding the application of antibiotics. The techniques implemented in this study provide evidence that there is no synergy between treatments at the selected concentrations and times.

Asunto(s)

Curcumina , Lacticaseibacillus rhamnosus , Lactococcus lactis , Aeromonas hydrophila , Animales , Antibacterianos/farmacología , Curcumina/farmacología , Pediococcus pentosaceus

RESUMEN

Listeria monocytogenes is one of the foodborne pathogens of most concern for food safety. To limit its presence in foods, bacteriocins have been proposed as natural bio-preservatives. Herein, a bacteriocin was produced on hemicellulose hydrolysate of sugarcane bagasse by Pediococcus pentosaceous ET34, whose genome sequencing revealed an operon with 100% similarity to that of pediocin PA-1. ET34 grown on hydrolysate-containing medium led to an increase in the expression of PA-1 genes and a non-optimized purification step sequence resulted in a yield of 0.8 mg·L-1 of pure pediocin (purity > 95%). Culture conditions were optimized according to a central composite design using temperature and hydrolysate % as independent variables and validated in 3-L Erlenmeyers. Finally, a process for scaled-up implementation by sugar-ethanol industry was proposed, considering green chemistry and biorefinery concepts. This work stands up as an approach addressing a future proper sugarcane bagasse valorisation for pediocin production.

Asunto(s)

Bacteriocinas , Saccharum , Celulosa , Pediocinas , Pediococcus , Pediococcus pentosaceus , Polisacáridos

RESUMEN

Pediococcus pentosaceus LBM 18 has shown potential as producer of an antibacterial and antifungal bacteriocin-like inhibitory substance (BLIS). BLIS inhibited the growth of spoilage bacteria belonging to Lactobacillus, Enterococcus and Listeria genera with higher activity than Nisaplin used as control. It gave rise to inhibition halos with diameters from 9.70 to 20.00 mm, with Lactobacillus sakei being the most sensitive strain (13.50-20.00 mm). It also effectively suppressed the growth of fungi isolated from corn grain silage for up to 25 days and impaired morphology of colonies by likely affecting fungal membranes. These results point out that P. pentosaceus BLIS may be used as a new promising alternative to conventional antibacterial and antifungal substances, with potential applications in agriculture and food industry as a natural bio-controlling agent. Moreover, cytotoxicity and cell death induction tests demonstrated cytotoxicity and toxicity of BLIS to human colon adenocarcinoma Caco-2cells but not to peripheral blood mononuclear cells, with suggests possible applications of BLIS also in medical-pharmaceutical applications.

Asunto(s)

Antiinfecciosos/farmacología , Productos Biológicos/farmacología , Pediococcus pentosaceus/química , Antibacterianos/química , Antibacterianos/farmacología , Antiinfecciosos/química , Antifúngicos/química , Antifúngicos/farmacología , Bacteriocinas/química , Bacteriocinas/farmacología , Productos Biológicos/química , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Pruebas de Sensibilidad Microbiana , Análisis Espectral

RESUMEN

The growing demand of consumers for synthetic chemical-free foods has increased the search for natural preservatives such as bacteriocins and bacteriocin-like inhibitory substances (BLIS) to give them adequate microbiological safety, sensory characteristics, and shelf life. In this study, the antimicrobial activity of BLIS produced by Pediococcus pentosaceus ATCC 43200 was compared with that of nisin. Lactobacillus sakei ATCC 15521, Listeria seeligeri NCTC 11289, Enterococcus En2052 and En2865, and Listeria monocytogenes CECT 934 and NADC 2045 exhibited larger inhibition halos in BLIS-treated than in Nisaplin-treated samples, unlike Listeria innocua NCTC 11288. In artificially contaminated ready-to-eat pork ham, BLIS was effective in inhibiting the growth of L. seeligeri NCTC 11289 for 6 days (counts from 1.74 to 0.00 log CFU/g) and ensured lower weight loss (2.7%) and lipid peroxidation (0.63 mg MDA/kg) of samples compared with the control (3.0%; 1.25 mg MDA/kg). At the same time, coloration of ham samples in terms of luminosity, redness, and yellowness as well as discoloration throughout cold storage was not influenced by BLIS or Nisaplin taken as a control. These results suggest the potential use of P. pentosaceus BLIS as a biopreservative in meat and other food processing industries.

Asunto(s)

Antibacterianos/farmacología , Bacteriocinas/farmacología , Conservantes de Alimentos/farmacología , Listeria/efectos de los fármacos , Pediococcus pentosaceus/metabolismo , Carne de Cerdo/microbiología , Animales , Recuento de Colonia Microbiana , Microbiología de Alimentos , Almacenamiento de Alimentos , Listeria/crecimiento & desarrollo , Nisina/farmacología , Carne de Cerdo/análisis

RESUMEN

AIMS: We aimed to evaluate some specific conditions for growth of Pediococcus pentosaceus ST65ACC and its bacteriocin expression through ABC transporters; to purify the bacteriocin and determine its sequence; and to evaluate the cytotoxicity potential of the purified bacteriocin(s). METHODS AND RESULTS: The results presented for growth behaviour of P. pentosaceus ST65ACC showed that the bacterial growth was slightly influenced when cultured in MRS broth with different amounts of inoculum: 1, 2, 5 and 10%. The bacteriocin activity increased when 5 and 10% inocula were used. The carbon source (glucose) used in different amounts (1, 2, 3 or 4%) had no significant effect on growth and bacteriocin production. The studied strain P. pentosaceus ST65ACC was able to metabolize xylooligosaccharide (XOS) as the sole carbon source, resulting in the production of an antimicrobial peptide. The genes involved in the ABC transport system and sugar metabolism of P. pentosaceus ST65ACC were expressed at different levels. The bacteriocin produced by P. pentosaceus ST65ACC was partially purified by precipitation with ammonium sulphate (40% saturation), followed by reversed-phase liquid chromatography, resulting in the identification of an active bacteriocin. Tandem mass spectrometry was used to identify the partial sequence KYYGNGVTCGKHSCSVDWGK sharing high similarity to coagulin A. The semi-purified bacteriocin had low cytotoxicity based on estimated values for maximal nontoxic concentration (MNC) and cytotoxicity concentration (CC50 ). CONCLUSIONS: The bacteriocin produced by P. pentosaceus ST65ACC is similar to coagulin, with low cytotoxicity, strong antimicrobial activity and possible additional metabolite routes in the producer cell. In addition to MRS broth, bacteriocin was produced also in medium containing XOS (as the single carbon source). SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this is the first report of evaluation of the role of ABC transporters in the expression of bacteriocin by P. pentosaceus, cultured in MRS and XOS.

Asunto(s)

Bacteriocinas/genética , Queso/microbiología , Leche/microbiología , Pediococcus pentosaceus/metabolismo , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacteriocinas/biosíntesis , Bacteriocinas/aislamiento & purificación , Bacteriocinas/farmacología , Expresión Génica , Concentración de Iones de Hidrógeno , Pediococcus pentosaceus/química , Pediococcus pentosaceus/genética , Pediococcus pentosaceus/crecimiento & desarrollo

RESUMEN

The presence of contaminants such as aflatoxins (AFs) in dairy products constitutes a serious risk to the health of consumers, especially children who are most sensitive to the adverse effects of AFs. The presence of Aflatoxin M1 (AFM1) in milk is a public health problem since dairy products are massively consumed worldwide. The aim of the present work was to select microorganisms capable of reducing AFM1 entry into the food chain through adsorption/degradation strategies. Moreover, the toxicity of AFM1 degradation products was evaluated. All tested strains had the capacity to adsorb 19%-61% AFM1 in milk. These strains also had the ability to degrade AFM1 into metabolites less toxic than the original toxin. Moreover, this is the first study to report harmless and probiotic Pediococcus pentosaceus and Kluveromyces marxianus have the ability to adsorb and degrade AFM1 to less toxic metabolites in milk.

Asunto(s)

Aflatoxina M1/metabolismo , Inactivación Metabólica , Leche/microbiología , Probióticos/farmacología , Adsorción , Aflatoxina M1/toxicidad , Animales , Artemia/efectos de los fármacos , Contaminación de Alimentos , Kluyveromyces/metabolismo , Pediococcus pentosaceus/metabolismo

RESUMEN

To improve bacteriocin-like inhibitory substance (BLIS) production by Pediococcus pentosaceus ATCC 43200, the influence of pH as well as the addition of sugars-either prebiotic (inulin) or not (sucrose)-on its metabolism were investigated. This strain was grown at pH 5.0 or 6.0 either in glucose-based MRS medium (control) or after addition of 0.5, 1.0 or 1.5% (w/w) sucrose and inulin (GSI-MRS) in the same percentages. In the control medium at pH 5.0, cell mass concentration after 48 h of fermentation (Xmax = 2.26 g/L), maximum specific growth rate (µmax = 0.180 h-1) and generation time (Tg = 3.84 h) were statistically coincident with those obtained in supplemented media. At pH 6.0 some variations occurred in these parameters between the control medium (Xmax = 2.68 g/L; µmax = 0.32 h-1; Tg = 2.17 h) and the above supplemented media (Xmax = 1.90, 2.52 and 1.86 g/L; µmax = 0.26, 0.33 and 0.32 h-1; Tg = 2.62, 2.06 and 2.11 h, respectively). Lactate production was remarkable at both pH values (13 and 16 g/L) and improved in all supplemented media, being 34 and 54% higher than in their respective control media, regardless of the concentration of these ingredients. Cell-free supernatant of the fermented control medium at pH 5.0 displayed an antimicrobial activity against Enterococcus 101 5.3% higher than that at pH 6.0 and even 20% higher than those of all supplemented media, regardless of the concentration of supplements. BLIS production was favored either at pH 5.0 or in the absence of any additional supplements, which were able, instead, to stimulate growth and lactate production by P. pentosaceus.

Asunto(s)

Bacteriocinas/biosíntesis , Pediococcus pentosaceus/crecimiento & desarrollo , Pediococcus pentosaceus/metabolismo , Antibacterianos/biosíntesis , Antibacterianos/farmacología , Bacteriocinas/farmacología , Medios de Cultivo/química , Fermentación , Microbiología de Alimentos/métodos , Concentración de Iones de Hidrógeno , Ácido Láctico/metabolismo , Azúcares/metabolismo

RESUMEN

The effects of new strains of lactic acid bacteria on alfalfa silage fermentation were evaluated. The experiment was performed using a completely randomized design (with three replicates) based on a 6 × 6 factorial assay with 6 inoculants (I): Control (CTRL), Commercial inoculant (CI), Lactobacillus pentosus 14.7SE (LPE), Lactobacillus plantarum 3.7E (LP), Pediococcus pentosaceus 14.15SE (PP), and Lactobacillus plantarum 3.7E + Pediococcus pentosaceus 14.15SE (LP + PP), and six fermentation periods (P): 1, 3, 7, 14, 28 and 56 days. Alfalfa was wilted for 6 h in the field, which increased the dry matter content to 368 g/kg as fed. The CP and yeast population decreased during the fermentation process. Silage inoculated with the PP strain had the lowest pH values beginning at 14 d of fermentation and the lowest acetic acid concentration on the last day of fermentation. New strains more efficiently regulated enterobacteria and mold populations at days 56 and 28, respectively. Silages inoculated with the PP strain had a higher coefficient of in vitro dry matter digestibility than LP silages. All of the tested novel strains resulted in positive effects on at least one chemical property of the silage during the fermentation process. However, the adding of P. pentosaceus can be indicated as the better for silage quality considering the tested treatments in the present study.

Asunto(s)

Ácido Láctico/metabolismo , Lactobacillales/metabolismo , Medicago sativa/microbiología , Ensilaje/microbiología , Fermentación , Lactobacillales/genética , Lactobacillales/crecimiento & desarrollo , Lactobacillus plantarum/crecimiento & desarrollo , Lactobacillus plantarum/metabolismo , Medicago sativa/química , Nitrógeno/metabolismo , Pediococcus pentosaceus/crecimiento & desarrollo , Pediococcus pentosaceus/metabolismo

RESUMEN

Bacteriocinogenic Enterococcus hirae ST57ACC and Pediococcus pentosaceus ST65ACC strains, previously isolated from artisanal cheese, were evaluated for their safety with the aim to determine whether they could be used as beneficial strains, especially in the control of Listeria monocytogenes. Both isolates survived simulated gastrointestinal conditions and showed high levels of auto- and co-aggregation with L. monocytogenes, although the hydrophobicity of cells varied. Using the agar-spot test with 33 commercial drugs from different groups, only anti-inflammatory drugs and drugs containing loratadine and propranolol hydrochloride were able to affect the growth of the tested strains. Both strains were resistant to 3 out of 11 antibiotics tested by the disc diffusion method, and low frequencies of antibiotic resistance-encoding genes were observed by PCR analysis. Tested strains neither presented biogenic amine-related genes nor produced these substances. Aside from some antibiotic resistance characteristics, the tested strains were considered safe as they lack other virulence-related genes. E. hirae ST57ACC and P. pentosaceus ST65ACC both presented beneficial properties, particularly their ability to survive gastrointestinal conditions and to aggregate with L. monocytogenes, which can facilitate the elimination of this pathogen. Further studies should be conducted to better understand these interactions.

Asunto(s)

Antibiosis/fisiología , Queso/microbiología , Enterococcus hirae/fisiología , Listeria monocytogenes/crecimiento & desarrollo , Pediococcus pentosaceus/fisiología , Farmacorresistencia Microbiana , Enterococcus hirae/efectos de los fármacos , Enterococcus hirae/genética , Interacciones Hidrofóbicas e Hidrofílicas , Pediococcus pentosaceus/efectos de los fármacos , Pediococcus pentosaceus/genética

RESUMEN

Early vat bacterial biofilms developed spontaneously through contact with whey have been characterized on seven wood types (Castanea sativa Miller, Cedrus libani, A. Rich., Prunus avium L., Fraxinus ornus L., Juglans regia L., Pinus nigra J.F. Arnold and Populus nigra L.). The present study aimed to evaluate the influence of these biofilms on the microbiological, chemical, physical and sensory characteristics of PDO Vastedda della valle del Belìce (VdB) cheese, processed traditionally from raw ewe's milk using wooden tools. To this purpose, the experimental cheeses after 15 d of refrigerated storage were examined. Lactic acid bacteria (LAB) populations dominated the microbial community of all samples. The species more frequently identified were Lactococcus lactis among starter LAB and Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus fermentum and Pediococcus pentosaceus among non starter LAB. Culture-independent analysis of microbiota diversity was performed by MiSeq Illumina that identified Streptococcus as major group followed by members of Enterobacteriaceae family, Lactococcus and Lactobacillus. Generally, the seven tree species did not negatively affect the physicochemical composition of VdB cheeses. Chestnut (both Sicilian and Calabrian) vats produced cheeses with significant lower hue angle (a*/b*) than other wood types. Among chemical parameters, significant variations were registered for aw, primary and secondary lipid oxidation state (significantly lower for the VdB cheeses produced with poplar wood), and volatile organic compounds (VOCs). The significant differences detected among the VOCs emitted from cheeses were not perceived by the panelists who recognized all cheeses from the different trials as similar. This study confirmed the suitability of cedar, cherry, ash, walnut, black pine and poplar as alternative woods to chestnut for the production of the wooden vats employed in cheese making for the Sicilian traditional dairy productions.

Asunto(s)

Biopelículas , Queso/microbiología , Microbiota , Adulto , Animales , Queso/análisis , Fenómenos Químicos , Color , Ácidos Grasos/análisis , Manipulación de Alimentos , Microbiología de Alimentos , Humanos , Lactobacillales/aislamiento & purificación , Limosilactobacillus fermentum/aislamiento & purificación , Lacticaseibacillus rhamnosus/aislamiento & purificación , Lactococcus/aislamiento & purificación , Lactococcus lactis/aislamiento & purificación , Metabolismo de los Lípidos , Persona de Mediana Edad , Leche/microbiología , Pediococcus pentosaceus/aislamiento & purificación , Fenotipo , Polifenoles/análisis , Análisis de Secuencia de ADN , Ovinos , Streptococcus/aislamiento & purificación , Compuestos Orgánicos Volátiles/análisis , Adulto Joven

RESUMEN

Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria (LAB), which have a large spectrum of action against spoilage bacteria and foodborne pathogens. However, when not entirely characterized, they are alternatively called bacteriocin-like inhibitory substances (BLIS). Pediococcus pentosaceus ATCC 43200 grew and produced BLIS optimally when cultivated anaerobically in bioreactor for 24 h at 30 °C and 200 rpm in De Man, Rogosa and Sharp (MRS) medium supplemented with 1.5% peptone. Under such optimal conditions, the cell mass concentration (3.41 g/L) was 66% higher, the generation time (1.28 h) 38% shorter and the BLIS activity against different indicator strains significantly higher than in MRS medium without any supplement taken as a control, and the exponential phase started 4 h before. The agar diffusion method showed BLIS inhibition halos against LAB strains with diameter in the range 11.0-19.5 mm and specific areas between 377.1 and 2654.6 mm2/mL, while BLIS activity against Listeria strains was better quantified by the liquid medium assay that showed, for the fermented broth without any dilution, 100 and 50% inhibition of Listeria innocua and Listeria seeligeri growth, respectively. These results highlight the potential of P. pentosaceus BLIS as a natural antimicrobial for application in the food industry.

Asunto(s)

Bacteriocinas/farmacología , Pediococcus pentosaceus/metabolismo , Pediococcus pentosaceus/fisiología , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Bacteriocinas/metabolismo , Reactores Biológicos , Microbiología de Alimentos , Listeria monocytogenes/efectos de los fármacos , Pediococcus/metabolismo

RESUMEN

Um dos grandes desafios nas indústrias alimentícia, farmacêutica e agropecuária é a busca por novos compostos para substituir os antibióticos. Como possíveis candidatos estão as bacteriocinas para serem utilizados paralelamente aos antibióticos ou até substituí-los. As bactérias ácido-láticas podem produzir substâncias inibitórias semelhantes às bacteriocinas (BLIS - bacteriocin-like inhibitory substances) que possuem efeito bacteriostático ou bactericida contra diferentes grupos de bactéria sendo largamente utilizadas como bioconservantes alimentares. Neste contexto, o objetivo deste trabalho foi o emprego de um resíduo agroindustrial, o hidrolisado de bagaço de cana-de-açúcar, como fonte de carbono em cultivos fermentativos para produção do BLIS pela cepa Pediococcus pentosaceus ET 34. Resultados revelaram que as células de ET34 foram capazes de crescer utilizando este resíduo agroindustrial como fonte de carbono e ensaios utilizando planejamento fatorial demonstraram que a agitação não influencia na produção de BLIS. Ao escalonar o cultivo em biorreatores, foi verificado que tanto o crescimento como a atividade antimicrobiana foram semelhantes aos obtidos em bancada com exceção da condição de 25% (v/v) de HBC (hidrolisado de bagaço de cana) que devido a maior viscosidade do meio, resultou em uma diminuição no crescimento e de produção de BLIS. O BLIS produzido por células de ET34 utilizando o HBC como fonte de carbono foi parcialmente purificado por sulfato de amônio e demonstrou atividade contra Listeria monocytogenes ATCC 934 e Salmonella enterica CECT 724. Desta maneira, pode-se concluir que Pediococcus pentosaceus ET34 foi capaz de crescer em meio contendo HBC como fonte de carbono produzindo BLIS em seu sobrenadante com ação frente a diferentes bactérias patogênicas. A possibilidade de utilizar uma fonte alternativa de carbono pode diminuir o custo de processo consideravelmente. Além disso, ensaios de planejamento fatorial, superfície de resposta e escalonamento em biorreator de bancada indicaram que concentrações baixas de HBC (5-15%, v/v) a 35 °C resultaram na maior produção de BLIS

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The great challenge in the food, pharmaceutical and agricultural industries is the search for new compounds to replace antibiotics. Bacteriocins are possible candidates that can be used in parallel with the antibiotics or even to replace them. Lactic-acid bacteria can produce bacteriocin inhibitory substances (BLIS - bacteriocin-like inhibitory substances) that have a bacteriostatic or bactericidal effect against different bacterial species and are widely used as food bioconservatives. In this context, the aim of this work was to use of an agroindustrial waste, hydrolyzed sugarcane bagasse, as a carbon source in fermentative cultures for the production of BLIS by Pediococcus pentosaceus ET 34 strain. Results revealed that ET34 cells were able to grow using this agroindustrial residue as a carbon source, and trials using factorial design showed that agitation did not influence on the production of BLIS. When it was perform cultivation scale up in bioreactors, it was verified that both the growth and the antimicrobial activity were similar to those obtained in the workbench with the exception of the condition of 25% (v/v) of HBC (sugarcane bagasse hydrolyzate) that due to its higher viscosity, resulted in a decrease in growth and BLIS production. BLIS produced by ET34 cells using HBC as a carbon source that was partially purified by ammonium sulfate showed activity against Listeria monocytogenes ATCC 934 and Salmonella enterica CECT 724. Thus, it can be concluded that Pediococcus pentosaceus ET34 was able to grow in medium containing HBC as carbon source producing BLIS in its supernatant with action against different pathogenic bacteria. The possibility of using an alternative carbon source can greatly reduce the process cost. In addition, factorial design, response surface and scale up trials in bench bioreactors indicated that low concentrations of HBC (5-15% v/v) at 35 ºC resulted in higher BLIS production

Asunto(s)

Residuos/clasificación , Pediococcus pentosaceus/clasificación , Pediocinas/análisis , Saccharum

RESUMEN

Six isolates (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, and Ac22Pd) of Pediococcus pentosaceus from sheep milk were tested for safety and for probiotic and technological potential. The results showed that none of the isolates were able to produce biogenic amines or virulence factors. The isolates tested showed low hydrophobicities, high auto-aggregation capacities and co-aggregation with L. monocytogenes ATCC 7644, L. sakei ATCC 15521 and E. faecalis ATCC 19444, but none produced ?-galactosidase and bacteriocins. The isolates did not show growth at pH values 3 and 12, while in a pH range from 4 to 10 the growth was variable. In the absence of bile, all the isolates showed growth, with suppression at bile concentrations of 0.1%, 0.3%, 0.6% and 1.0%. In the disc-diffusion test, the isolates tested were resistant to oxacillin, sulfatrimethoprim and vancomycin but were sensitive to chloramphenicol and tetracycline. The isolates showed variable responses to penicillin G and were resistant to most of the drugs tested, except for amoxicillin trihydrate and ibuprofen. All cultures showed a high milk-acidification capacity after 24 hours and none produced exopolysaccharides. The isolates of P. pentosaceus were able to produce diacetyl; however, no culture showed extracellular proteolytic activity and the autolysis varied from 21.3% to 30.5% after 24 h. The isolates grew at NaCl concentrations ...

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Testes de avaliação de potencial de segurança, probiótico e tecnológicos foram realizados em seis isolados de Pediococcus pentosaceus (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, Ac22Pd) provenientes de leite de ovelha. Os resultados obtidos demonstraram que nenhum dos isolados foi capaz de produzir aminas biogênicas ou fatores de virulência. Os isolados testados apresentaram baixa hidrofobicidade, alta capacidade de autoagregação e coagregação com L. monocytogenes ATCC 7644, L. sakei ATCC 15521 e E. faecalis ATCC 19444, porém nenhum produziu ?-galactosidase e bacteriocinas. Não foi observado desenvolvimento dos isolados em pH 3 e 12, sendo que na faixa de pH de 4 a 10 o desenvolvimento foi variável. Na ausência de bile todos os isolados apresentaram desenvolvimento, observando-se supressão quando em concentrações de 0,1%, 0,3%, 0,6% e 1%. No teste de disco-difusão os isolados testados foram resistentes à oxaciclina, sulfatrimetropim e vancomicina, mas foram sensíveis ao cloranfenicol e à tetraciclina e com resultados variáveis para a penicilina G e foram resistentes à maioria dos medicamentos testados, exceto à amoxicilina tri-hidratada e ibuprofeno. Foi observada acidificação do leite somente após 24 h e nenhum produziu exopolissacarídeos. Os isolados de P. pentosaceus foram capazes de produzir diacetil, no entanto, nenhuma cultura apresentou atividade proteolítica extracelular e a...

Asunto(s)

Animales , Leche/microbiología , Ovinos , Pediococcus pentosaceus/aislamiento & purificación , Probióticos , Tecnología de Alimentos , Técnicas In Vitro/métodos

RESUMEN

Six isolates (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, and Ac22Pd) of Pediococcus pentosaceus from sheep milk were tested for safety and for probiotic and technological potential. The results showed that none of the isolates were able to produce biogenic amines or virulence factors. The isolates tested showed low hydrophobicities, high auto-aggregation capacities and co-aggregation with L. monocytogenes ATCC 7644, L. sakei ATCC 15521 and E. faecalis ATCC 19444, but none produced ?-galactosidase and bacteriocins. The isolates did not show growth at pH values 3 and 12, while in a pH range from 4 to 10 the growth was variable. In the absence of bile, all the isolates showed growth, with suppression at bile concentrations of 0.1%, 0.3%, 0.6% and 1.0%. In the disc-diffusion test, the isolates tested were resistant to oxacillin, sulfatrimethoprim and vancomycin but were sensitive to chloramphenicol and tetracycline. The isolates showed variable responses to penicillin G and were resistant to most of the drugs tested, except for amoxicillin trihydrate and ibuprofen. All cultures showed a high milk-acidification capacity after 24 hours and none produced exopolysaccharides. The isolates of P. pentosaceus were able to produce diacetyl; however, no culture showed extracellular proteolytic activity and the autolysis varied from 21.3% to 30.5% after 24 h. The isolates grew at NaCl concentrations ...(AU)

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Testes de avaliação de potencial de segurança, probiótico e tecnológicos foram realizados em seis isolados de Pediococcus pentosaceus (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, Ac22Pd) provenientes de leite de ovelha. Os resultados obtidos demonstraram que nenhum dos isolados foi capaz de produzir aminas biogênicas ou fatores de virulência. Os isolados testados apresentaram baixa hidrofobicidade, alta capacidade de autoagregação e coagregação com L. monocytogenes ATCC 7644, L. sakei ATCC 15521 e E. faecalis ATCC 19444, porém nenhum produziu ?-galactosidase e bacteriocinas. Não foi observado desenvolvimento dos isolados em pH 3 e 12, sendo que na faixa de pH de 4 a 10 o desenvolvimento foi variável. Na ausência de bile todos os isolados apresentaram desenvolvimento, observando-se supressão quando em concentrações de 0,1%, 0,3%, 0,6% e 1%. No teste de disco-difusão os isolados testados foram resistentes à oxaciclina, sulfatrimetropim e vancomicina, mas foram sensíveis ao cloranfenicol e à tetraciclina e com resultados variáveis para a penicilina G e foram resistentes à maioria dos medicamentos testados, exceto à amoxicilina tri-hidratada e ibuprofeno. Foi observada acidificação do leite somente após 24 h e nenhum produziu exopolissacarídeos. Os isolados de P. pentosaceus foram capazes de produzir diacetil, no entanto, nenhuma cultura apresentou atividade proteolítica extracelular e a...(AU)

Asunto(s)

Animales , Pediococcus pentosaceus/aislamiento & purificación , Leche/microbiología , Ovinos , Probióticos , Técnicas In Vitro/métodos , Tecnología de Alimentos

RESUMEN

Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria (LABs), which exhibit a large spectrum of action against spoilage bacteria and foodborne pathogens. However, when this bacteriocin has not been completely characterized regarding its amino acid and the nucleotide sequences of the corresponding gene, the qualified term bacteriocin-like inhibitory substance (BLIS) is recommended. In order to increase the antimicrobial activity of bacteriocins, the ability of probiotics LABs, such as Pediococcus pentosaceus, to ferment different carbon and nitrogen sources has been studied. For the development of an improved culture medium, carbon and nitrogen sources must be considered as nutrients responsible for cell growth and bacteriocin production. The best condition, after 48 h of cultivation, for growth (3.420 g/L) and for BLIS production by Pediococcus pentosaceus ATCC 43200 was in Man, Rogosa and Sharp (MRS) culture medium supplemented with 1.5% peptone, initial pH 6.0 and under the following culture conditions: anaerobiosis, 30oC and agitation of 200 rpm. Compared with control (MRS without supplement), the growth of Pediococcus was significantly lower (1.995 g/L) as well as it reduced significantly its generation time from 2.05 h (control) to 1.28 h (MRS supplemented), a reduction of approximately 62.5%. Moreover, addiction of peptone to MRS medium promoted reduction of 4 h to the Pediococcus exponential phase onset. Regarding BLIS antimicrobial activity, addition of nitrogen source to MRS medium was also quite significant. Through the agar diffusion method, BLIS showed inhibition halos between 12.50 and 19.50 mm against LABs strains (Lactobacillus sakei ATCC 15521, Lactobacillus plantarum CECT 221 and Carnobacterium piscicola CECT 4020). Against Listeria strains (Listeria innocua NCTC 111288 and Listeria seeligeri NCTC 11289), their antimicrobial activity was better detected in liquid medium assay, evaluating the minimal inhibitory concentration of 50%. BLIS was able to inhibit 60 and 100% of L. seeligeri and L. innocua, respectively, as well as, diluted 1x (v/v) in water was able to inhibit 100% growth of both Listeria. BLIS 17 showed also good results as food preservative when applied in ready-to-eat pork ham artificially contaminated with L. seeligeri in vacuum-package at 4oC during shelf life of 10 days. BLIS was able to maintain low Listeria multiplication, lower samples weight loss, low lipid peroxidation and good color parameters during samples storage. Results demonstrated the importance of optimizing the culture medium to increase microbial mass, to produce and to improve the activity of this antimicrobial molecule. Moreover, results also suggest the possible application of BLIS as a natural food preservative

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Bacteriocinas são peptídeos produzidos por várias espécies de bactérias, especialmente bactérias ácido-láticas (BALs) e apresentam um amplo espectro de ação contra bactérias deteriorantes e patógenos de origem alimentar. Entretanto, quando estas bacteriocinas não foram completamente caracterizadas quanto a sequência de seus nucleotídeos e do seu gene correspondente, é recomendada a denominação de substância semelhante a bacteriocina (BLIS). Para aumentar a atividade antimicrobiana de bacteriocinas, a habilidade de BALs probióticas, como Pediococcus pentosaceus, em fermentar diferentes fontes de carbono e nitrogênio tem sido estudado. Para o desenvolvimento de um meio de cultura melhorado, fontes de carbono e nitrogênio devem ser consideradas como nutrientes responsáveis pelo crescimento celular e pela produção de bacteriocina. A melhor condição, após 48 h de cultivo, para o crescimento (3,420 g/L) e para a produção de BLIS por P. pentosaceus ATCC 43200 foi em meio de cultivo Man, Rogosa e Sharp (MRS) suplementado com 1,5% de peptona, pH inicial 6,0 e sob as seguintes condições de cultivo: anaerobiose, 30oC e agitação de 200 rpm. Comparado ao controle (MRS sem suplementação), o crescimento de Pediococcus foi significativamente menor (1,995 g/L) assim, como também, reduziu significativamente o tempo de geração de 2,05 h (controle) para 1,28 h (MRS suplementado), uma redução de aproximadamente 62,5%. Além disso, a adição de peptona ao meio MRS promoveu redução de 4 h para o início da fase exponencial de Pediococcus. Quanto a atividade antimicrobiana de BLIS, a adição de fonte de nitrogênio ao meio MRS também foi bastante significativa. Através do método ágar difusão, BLIS apresentou halos de inibição entre 12,50 a 19,50 mm contra cepas de BALs (Lactobacillus sakei ATCC 15521, Lactobacillus plantarum CECT 221 e Carnobacterium piscicola CECT 4020). Contra cepas de Listeria (Listeria innocua NCTC 11288 e Listeria seeligeri NCTC 11289), a sua atividade inibitória foi melhor detectada em meio líquido, através da determinação da concentração mínima inibitória de 50%. BLIS sem diluição foi capaz de inibir 60 e 100% de L. seeligeri e L. innocua, 15 respectivamente, assim como, diluído 1x (v/v) em água foi capaz de inibir 100% o crescimento de ambas Listeria. BLIS também apresentou bons resultados como conservante de alimento quando aplicado em presunto contaminado artificialmente com L. seeligeri e armazenado a 4oC a vácuo por 10 dias. BLIS foi capaz de manter baixa a multiplicação de Listeria, menor perda de peso das amostras, baixa peroxidação lipídica e bons parâmetros de cor durante o armazenamento das amostras. Os resultados demonstraram a importância de se otimizar meio de cultivo tanto para o aumento da massa microbiana como para a produção e melhoramento da atividade desta molécula antimicrobiana. Além disso, os resultados também sugerem a possível aplicação de BLIS como conservante natural de alimentos

Asunto(s)

Bacteriocinas/análisis , Bacteriocinas/farmacología , Antiinfecciosos/clasificación , Ácido Láctico/efectos adversos , Pediococcus pentosaceus/patogenicidad , Conservantes de Alimentos