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Frontiers in Microbiology 2021Stress physiology of lactic acid bacteria (LAB) is crucial to their ecological fitness and applicational implications. As a self-imposed stress, lactic acid is the major...
Stress physiology of lactic acid bacteria (LAB) is crucial to their ecological fitness and applicational implications. As a self-imposed stress, lactic acid is the major final metabolic product of LAB and its accumulation can be detrimental to bacterial cells. However, the relationship between LAB carbohydrate metabolism, the primary energy supplying bioactivities, and lactic acid stress responses is not fully understood. has been recognized as an important cell factory and demonstrated probiotic activities. This study investigated behavior of under lactic and acetic acid stresses, particularly with supplementations of metabolizable carbohydrates. Lactic and acetic acid retain similar growth stagnation effect, and both resulted in cell death in . All metabolizable carbohydrates improved bacterial survival compared to lactic acid control, while xylooligosaccharides (XOS) exerted the highest viability protective efficacy, 0.82 log CFU/mL higher population survived than other carbohydrates after 30 h of incubation. RNA-seq pipeline showcased the intensive global transcriptional responses of to lactic acid, which caused significant regulations (more than 2 Log fold) of 16.5% of total mRNA coding genes. Glucose mainly led to gene suppressions (83 genes) while XOS led to gene up-regulations (19 genes) under lactic acid stress. RT-qPCR study found that RNA polymerase-centered transcriptional regulation is the primary regulatory approach in evaluated culture conditions. The synergy between lactic acid stress and carbohydrate metabolism should be attentively contemplated in future studies and applications.
PubMed: 34603267
DOI: 10.3389/fmicb.2021.736411 -
Scientific Reports Jul 2020Pediococcus pentosaceus LBM 18 has shown potential as producer of an antibacterial and antifungal bacteriocin-like inhibitory substance (BLIS). BLIS inhibited the growth...
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.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Antifungal Agents; Bacteriocins; Biological Products; Cell Survival; Dose-Response Relationship, Drug; Humans; Leukocytes, Mononuclear; Microbial Sensitivity Tests; Pediococcus pentosaceus; Spectrum Analysis
PubMed: 32704020
DOI: 10.1038/s41598-020-68922-2 -
Frontiers in Microbiology 2018MZF16 has been isolated from artisanal Tunisian meat so called "Dried Ossban," an original ecological niche, and identified by MALDI-TOF mass spectrometry and 16S rDNA...
MZF16 has been isolated from artisanal Tunisian meat so called "Dried Ossban," an original ecological niche, and identified by MALDI-TOF mass spectrometry and 16S rDNA sequencing. This bacterium showed a high tolerance to gastric stress conditions, and toward bile salts. MZF16 also demonstrated a hydrophobic surface profile (high adhesion to xylene), autoaggregation, and adhesive abilities to the human intestinal Caco-2/TC7 cell line. These properties may help the bacterium colonizing the gut. Furthermore, MZF16 was found to be resistant to gentamycin and chloramphenicol but did not harbor any transferable resistance determinants and/or virulence genes. The data also demonstrated absence of cytotoxicity of this strain. Conversely, MZF16 can slightly stimulate the immune system and enhance the intestinal epithelial barrier function. Moreover, this bacterium has been shown to be highly active against spp. due to bacteriocin production. Characterization of the bacteriocin by PCR amplification, sequencing and bioinformatic analyses revealed that MZF16 produces a bacteriocin 100% identical to coagulin, a pediocin-like inhibitory substance produced by . To our knowledge, this is the first report that highlights the production of a pediocin 100% identical to coagulin in a strain. As coagulin, pediocin MZF16 has the consensus sequence YYGNGVXCXXXXCXVXXXXA (X denotes any amino acid), which confirms its belonging to class IIa bacteriocins, and its suitability to preserve foods from development. According to these results, MZF16 can be proposed as a probiotic and bioprotective agent for fermented foods, including Tunisian dry meat and sausages. Further investigations will aim to study the behavior of this strain in meat products as a component of functional food.
PubMed: 30473681
DOI: 10.3389/fmicb.2018.02607 -
Foods (Basel, Switzerland) Jun 2022In this study, eight lactic acid bacteria (LAB) strains, previously isolated from traditional and gluten-free sourdoughs, and selected for their potential in improving...
In this study, eight lactic acid bacteria (LAB) strains, previously isolated from traditional and gluten-free sourdoughs, and selected for their potential in improving the sensory and rheological quality of bakery products, were screened against some common spoilage agents. The anti-mould activity was tested using strains of the species , , and Regarding the antibacterial activity, it was assessed against four strains of the species , , and . Furthermore, LAB strains were evaluated for their ability to produce exopolysaccharides, which are gaining considerable attention for their functional properties and applicability in different food industrial applications. A strain-specific behaviour against the moulds was observed. In particular, ITEM 5356 was completely inhibited by all the LAB strains. Regarding the antibacterial activity, the strains UMCC 3011, UMCC 2996, and UMCC 3010 showed wide activity against the tested pathogens. Moreover, all the LAB strains were able to produce exopolysaccharides, which were preliminarily characterized. The assessed features of the LAB strains allow us to consider them as promising candidates for single or multiple starter cultures for food fermentation processes.
PubMed: 35804730
DOI: 10.3390/foods11131914 -
Microorganisms Nov 2022In this study, we investigated the immune-enhancing and anti-viral effects of germinated (GRC) fermented with SC11 (GRC-SC11) isolated from a salted small octopus. The...
Immunostimulatory Activity of Fermented with SC11 Isolated from a Salted Small Octopus in Cyclophosphamide-Induced Immunocompromised Mice and Its Inhibitory Activity against SARS-CoV 3CL Protease.
In this study, we investigated the immune-enhancing and anti-viral effects of germinated (GRC) fermented with SC11 (GRC-SC11) isolated from a salted small octopus. The cordycepin, β-glucan, and total flavonoid contents increased in GRC after SC11 fermentation. GRC-SC11 inhibits 3CL protease activity in severe acute respiratory syndrome-associated coronavirus (SARS-CoV). GRC-SC11 significantly increased thymus and spleen indices in immunocompromised mice. The rate of splenocyte proliferation was higher in GRC-SC11-treated immunocompromised mice than that in GRC-treated immunocompromised mice in the presence or absence of concanavalin A. In addition, GRC-SC11 increased the phagocytic activity and nitric oxide production in immunocompromised mice. The mRNA expression of interferon-gamma (IFN-γ), interferon-alpha (IFN-α), and interferon-stimulated gene 15 (ISG15) was up-regulated in GRC-SC11 treated RAW 264.7 macrophages, compared to GRC. Our study indicates that GRC-SC11 might be a potential therapeutic agent for immunocompromised patients who are vulnerable to SARS-CoV infection.
PubMed: 36557573
DOI: 10.3390/microorganisms10122321 -
BioMed Research International 2020can cause significant morbidity and mortality in humans and economic loss in the animal industry. Improving the innate immunity is an effective method to prevent...
can cause significant morbidity and mortality in humans and economic loss in the animal industry. Improving the innate immunity is an effective method to prevent infection. is a Gram-positive coccus which had probiotics properties. Numerous previously published studies reported that probiotics were beneficial to gut microbiota by changing the intestinal flora structure and inhibiting the harmful microbial growth to enhance the innate immunity. We investigated the immunological effects of on Salmonella-infected chickens by the following experiment. A total of 120 broilers from AA line were fed and divided into 2 groups (treated and control groups) for the experiment from day 1. The control group was fed with the basic diet, while the treated group was fed with the basic diet adding microcapsule with the bacterial concentration of 1 g/kg in the feed and bacterial counts 2.5 × 10 CFU/g. All the birds were given with 0.5 ml of bacterial suspension (10 CFU/ml) through oral cavity at day 9. The number of dead birds was recorded and used in the analysis. The bacterial culture method and quantitative real-time PCR analysis were used to evaluate the effects of on chickens infected with and to ascertain the mechanism of the effect. The results showed that the could restrain the pathogenicity of and reduce the death rate from 44.4% to 23.3%. The flora in the caecum exhibited "rising-declining" trends, and the gene (, , , , , , and ) expression pattern was different between the experimental and control group. as a probiotic may competitively inhibit the growth of and control the inflammatory response through regulating the gene expression which involved in the toll-like receptor pathway and inflammation pathway.
Topics: Animals; Avian Proteins; Cecum; Chickens; Gastrointestinal Microbiome; Gene Expression; Immunity, Innate; Pediococcus pentosaceus; Poultry Diseases; Probiotics; Salmonella Infections, Animal; Salmonella enteritidis; Signal Transduction; Toll-Like Receptors
PubMed: 33102586
DOI: 10.1155/2020/6416451 -
Foods (Basel, Switzerland) Dec 2022The effects of and on the nutritional-functional composition, structure, in vitro saliva-gastrointestinal digestion, and colonic fermentation behaviors of fermented...
The effects of and on the nutritional-functional composition, structure, in vitro saliva-gastrointestinal digestion, and colonic fermentation behaviors of fermented sweet potato residues (FSPR) were investigated. The FSPR was obtained under the condition of a solid-to-liquid ratio of 1/10, inoculation quantity of 1.5%, mixed bacteria ratio 1:1, fermentation time of 48 h, and fermentation temperature of 37 °C. The FSPR showed higher contents of soluble dietary fiber (15.02 g/100 g), total polyphenols content (95.74 mg/100 g), lactic acid (58.01 mg/g), acetic acid (1.66 mg/g), volatile acids (34.26%), and antioxidant activities. As exhibited by FTIR and SEM, the higher peak intensity at 1741 cm and looser structure were observed in FSPR. Further, the FSPR group at colonic fermentation time of 48 h showed higher content of acetic acid (1366.88 µg/mL), propionic acid (40.98 µg/mL), and butyric acid (22.71 µg/mL), which were the metabolites produced by gut microbiota using dietary fiber. Meanwhile, the abundance of and in the FSPR group was also improved. These results indicated that FSPR potentially developed functional foods that contributed to colonic health.
PubMed: 36613345
DOI: 10.3390/foods12010128 -
Microbiology Resource Announcements Apr 2022We report here the draft genome sequence of Pediococcus pentosaceus strain IMI 507024, a lactic acid bacterium isolated from fermented sausage in Kentucky...
We report here the draft genome sequence of Pediococcus pentosaceus strain IMI 507024, a lactic acid bacterium isolated from fermented sausage in Kentucky (Nicholasville, KY, USA). The strain is deposited in the Centre for Agriculture and Bioscience International (CABI) Culture Collection with the accession number IMI 507024.
PubMed: 35343777
DOI: 10.1128/mra.01216-21 -
Heliyon Nov 2023Lactic Acid Bacteria play an important role in the milk fermentation processes of traditional cheeses and have become an important target for the development of novel...
Lactic Acid Bacteria play an important role in the milk fermentation processes of traditional cheeses and have become an important target for the development of novel cheese cultures because of their ability to confer health benefits. This study aimed to evaluate the probiotic potential of 12 Lactic Acid Bacteria (LAB) strains previously isolated and molecularly identified from an artisanal Colombian Double-Cream Cheese. Probiotic properties, including safety (hemolysis and sensibility to antibiotics), pH and bile salt tolerance, auto-aggregation, cell surface hydrophobicity, antibacterial activity, and exopolysaccharide production, were examined. None of the strains were hemolytic, and (16, 18) and (28, 29) were found to be sensitive to all antibiotics. Moreover, all the strains tolerated pH (3.0, 6.5 and 8.0) and bile salt conditions (0.3, 0.6 and 1.0 % w/v). (16), (17), (18), (21,22), (24) and (29) exhibited medium autoaggregation and affinity to chloroform. Six of the strains exhibited a ropy exopolysaccharide phenotype. Antibacterial activity against foodborne pathogens, Typhimurium ATCC 14028, ATCC 19111, ATCC 25922 and ATCC 25923, was found to be strain dependent, with the strains 16, 18, 21, 26, 28 and 29 presenting a higher inhibition (>4 mm) against all of them. According to Principal Component Analysis, (16), (26), i (28), (29), and (21) showed strong probiotic properties. Our findings suggest that five strains out of the 12 sampled strains are potential probiotics that could be used in the processing of traditional dairy products on an industrial scale to improve their quality.
PubMed: 38027952
DOI: 10.1016/j.heliyon.2023.e21558 -
Food Technology and Biotechnology Mar 2015The objective of this study is to evaluate the antilisterial effect of T1, which was isolated from kimchi, and to assess its potential for extending the shelf life of...
The objective of this study is to evaluate the antilisterial effect of T1, which was isolated from kimchi, and to assess its potential for extending the shelf life of salmon and kimchi. T1 culture effectively inhibited proliferation of in a dose-dependent manner in a salmon-based medium. Antilisterial effect of the culture was stronger than that of nisin, an antibacterial peptide, as evidenced by lower minimum inhibitory concentration value (20 mg/mL) compared to nisin (over 20 mg/mL). T1 culture also effectively inhibited the growth of in salmon fillet. In particular, the culture (6 g per 100 mL) showed a stronger inhibitory effect than sodium hypochlorite (0.2 mg/mL), a disinfectant used in food processing. In kimchi fermentation, the treatment with T1 culture suppressed changes of acidity and pH during maturation. The inhibitory effect of the culture on kimchi lactic acid bacteria, which include and , led to a drastic decrease in maturation rates of kimchi. Moreover, sensory test on kimchi treated with T1 showed that the culture improved overall acceptability of kimchi, which can be observed in higher scores of sourness, texture, off-flavour and mouthfeel compared with untreated kimchi. The results of this study suggest that kimchi-derived T1 could be a potential antilisterial agent in fish products as well as a starter to control overmaturation of kimchi.
PubMed: 27904329
DOI: 10.17113/ftb.53.01.15.3754