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• Lactic acid bacteria were isolated from fermented black cherry fruit, which had never been investigated before and they are afforded generally regarded as safe status and have positive influence on gastrointestinal tract of human and other consumer animals. • The LAB strains exhibited strong survival properties and antimicrobial activities, highly desirable features for probiotic application against foodborne pathogens. • Salmonella paratyphi a sessile cells were effectively reduced after treatment with the CFS of lactiplantibacillus plantarum MYSAS1 and enterococcus faecium MYSAS4 all the in-vitro assays. Salmonella spp is one of the leading causes of bacterial foodborne illnesses worldwide resulting in acute gastroenteritis. The current study aimed to explore the inhibitory activity of two newly isolated probiotic candidates Lactiplantibacillus plantarum MYSAS1 and Enterococcus faecium MYSAS4 from fermented black cherry fruit, against Salmonella enterica subsp. enterica serovar Paratyphi A. Results demonstrated effective inhibitory activity of selected Lactic acid bacteria (LAB) strains against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella Paratyphi A. In addition, the cell-free supernatant (CFS) of both strains showed potent antimicrobial activity on growth of S. Paratyphi A were demonstrated by agar well diffusion, broth microdilution assay, in vitro time-kill assay, and co-culture experiments. Besides, Salmonella sessile cells were effectively reduced by 70% after treatment with the CFS of L. plantarum MYSAS1 and E. faecium MYSAS4, as determined by crystal violet and 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyltetra bromide (MTT) biofilm assays. The antimicrobial substances of CFS were thermostable but sensitive to pH neutralization, suggesting that the observed antisalmonella activity is likely due to organic acids. Liquid Chromatography- Tandem Mass Spectrometry (LC-MS/MS) analysis of CFS revealed that the antimicrobial activity is likely due to the presence of 11 different organic acids. The isolated strains exhibited important probiotic characteristics, such as sensitivity to most of the antibiotics tested (except vancomycin and kanamycin), anti-hemolytic activity, tolerance to acidic pH and 0.3% bile, and survival ability at different temperatures. L. plantarum MYSAS1 and E. faecium MYSAS4 also exhibited auto-aggregation and cell surface hydrophobicity of 45 and 80%, respectively. Our findings demonstrated important probiotic features isolated from black cherry fruits while inhibiting multiple pathogens, suggesting possible applications of these potential probiotic strains as alternatives for antibiotics and chemical preservatives in the veterinary and food sectors. [ABSTRACT FROM AUTHOR]

High-moisture mozzarella cheese (HMMC) is a highly perishable cheese with a short shelf life. In this study, the effects of UF cheese whey containing postbiotics from Lactobacillus acidophilus LA-5 (P-LA-5), Bifidobacterium animalis BB-12 (P-BB-12), and their combination on the microbial (i.e., psychrophiles, mesophiles, lactic acid bacteria, and mold-yeast population) and sensory properties of HMMC were investigated. Postbiotics were prepared in a cheese whey model medium as a novel growth media and used as a preserving liquid in HMMC. The results demonstrate that postbiotics reduced the growth of all microorganisms (1.5–2 log CFU/g reduction) and P-LA5 and P-BB12 had the highest antibacterial performance on mesophiles and psychrophiles, respectively. Mold and yeast had the highest susceptibility to the postbiotics. Postbiotics showed a significant effect on maintaining the microbial quality of HMMC during storage, proposing postbiotics as a new preserving liquid for HMMC. [ABSTRACT FROM AUTHOR]

Characterization of lactic acid bacteria (LAB) isolated from rarely studied fermentation substrates can lead to isolate unique microorganisms. In the present study, predominant LAB was isolated from fermented acorn using repeat of back-slopping process, and then the isolate was identified by PCR. Subsequently, probiotic properties of the isolate (including resistance to acid and bile, antibacterial, auto and co-aggregations, antibiotic susceptibility and blood hemolysis), as well as its antifungal effect were studied. Sequencing results of the PCR products led to the identification of Pediococcus acidilactici as predominant LAB isolate. The survival percentage of the isolate in continuous acid and bile treatment was equal to 72%. The inhibitory effect of the isolate on Bacillus cereus was also significantly (P<0.05) higher than the other foodborne indicator bacteria. Furthermore, crude cell free supernatant (CFS) obtained from LAB culture completely inhibit the growth ofB. cereus; meanwhile, its naturalized CFS had no inhibitory effect on Salmonella enterica. LAB isolate had also proper auto and co-aggregation (with E. coli) potentials and had no hemolytic activity. Antifungal activity of the isolate against Aspergillus niger was also verified. By considering the proper probiotic and antifungal potentials of the P. acidilactici isolated from fermented acorn it is possible to use the isolate as microbial starter, adjunct, probiotic and or protective culture in fermentation industries. [ABSTRACT FROM AUTHOR]

Oxidative stress is a metabolic condition characterized by excessive production of free radicals in the body. The condition leads to metabolic diseases including; aging, diabetes, atherosclerosis, myocardial infarction and cancer. Antioxidants are the mainstay to modulate the consequences of oxidative damage. Secondary metabolites from lactic acid producing bacteria possess antioxidant activity. The present study aimed at isolating and identifying antioxidant metabolites present in cell free supernatant (CFS) of broth culture of Lactobacillus brevis MG 000874. Thin layer chromatography (TLC) coupled bioautography of different fractions of methanol extract of CFS using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) model indicated antioxidant activity in ethyl acetate fraction. Fourier transform infrared (FTIR) spectroscopy of the isolated compound revealed the presence of aldehyde and alkyl functional groups. GC-MS analysis led to identification of four active compounds viz. a) L-proline, N-valeryl, hexyl ester b) Ergotaman-3',6',18-Trione,12'-Hydroxy-2'-Methyl-5'-(2-Methylpropyl) c) 2-Methylthiolane, S, S-Dioxide and d) Phenol, 3,5-Bis(1,1-Dimethylethyl). Findings of present study may be useful in developing antioxidant drugs from bacterial origin. [ABSTRACT FROM AUTHOR]

The present research was conducted to evaluate the antagonistic potential of lactic acid bacteria (LAB) isolates in vitro using agar well diffusion method. In this research, four LAB isolates were selected to investigate their antifungal and antibacterial activity against two phytopathogenic fungi and four pathogenic bacteria. Cell-free supernatants at different fold concentrations (50, 25 and 12.5) ml/l of the four LAB isolates were employed. It was found that all cell-free supernatant folds of the four selected LAB isolates were able to inhibit the growth of all phytopathogenic fungi (Fusarium oxysporum and Alternaria sp) and pathogenic bacteria (E. coli, Klebsiella sp, Salmonella sp, Staphyllococcus aureus). However, the degree of inhibition varied depending upon LAB isolate and microorganism involved. Some LAB isolates revealed effective inhibition activity while others exhibited lower response. Among different LAB isolates, lactobacillus bulgaricus exhibited the strongest antifungal activity against Fusarium oxysporum in all three cell-free supernatant fold concentrates. On the other hand, L. paracasei, L. acidophilus and L. rhamnosus cell-free supernatants showed higher inhibition activity against pathogenic bacteria whereas L. bulgaricus was least active. E. coli was the most inhibited bacterium by L. paracasei and L. acidophilus. LAB cell-free supernatants also showed wide spectrum inhibition activity against both gram positive and gram-negative bacteria. It was also found that the third fold concentrate showed higher inhibition activity than first- and second-fold concentrates against all tested microorganisms, except the second fold concentrate of L. acidophillus which showed higher inhibition effect against both tested fungi. Antibiotics were used to investigate [ABSTRACT FROM AUTHOR]

This study was designed to characterize one Lactic acid bacteria (LAB), Enterococcus ratti showing admirable antimicrobial potential. Out of 54 LAB strains isolated from herbivores, cell free supernatant (CFS) of one strain E. ratti was active against wide range of pathogens including Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus mirabilis. PCR amplification of enterocin genes indicated presence of entL50 A and entP. Time kill assay of foodborne pathogens in the presence of CFS further confirmed its bactericidal property. The antimicrobial component was stable at a wide range of pH (4-10) and temperature (4-100°C). The loss of activity with proteinase k and pepsin treatment indicated its proteinaceous nature. SDS-PAGE analysis confirmed production of short peptides of 20 and 30KDa Bioautography revealed 20kDa fraction was active against MRSA. Scanning Electron Micrograph further indicated that its bactericidal action involves damage to the cell wall. Our findings suggest safe nature of E. ratti MF183967 for consumer health. [ABSTRACT FROM AUTHOR]

This study investigated the effects of lactic acid bacteria (LAB) of goat's milk origin on growth and biofilm formation of two pathogenic strains viz. Pseudomonas aeruginosa and Staphylococcus aureus . Different LAB preparations such as untreated cell free supernatants (CFSs), pH neutralized CFS (N-CFS) and heat treated CFS (H-CFS) of lactobacilli were screened for their antimicrobial and biofilm inhibitory properties. The antagonistic activities were compared to L . acidophilus , a reference probiotic strain. In addition, metabolic activity of bacterial pathogens upon CFSs challenge was also determined by MTT assay. LAB CFSs inhibited pathogen growth to a varied degree. A decrease in the number of sessile pathogen cells was observed upon exposure with untreated CFS, under both post and co-incubation strategy. The CFS of GM12, GM13, GM15 and GM17 could effectively inhibit the biofilm formation of both the pathogens to a significant level (p < 0.05) varying between 72% and 86%. Upon principal component analysis of recorded data, untreated CFS from GM12 emerged to be most promising against both the test biofilm formers. N-CFS and H-CFS preparations also limited the biofilm formation, however to a lower extent than untreated form. As also determined by MTT assay, the metabolic activity of P. aeruginosa and S. aureus were significantly reduced upon CFS exposure. The light microscopic images depicted major disruption in the biofilm matrix of pathogenic strains upon CFS challenge. Findings from this study indicate that the Lactobacillus strains of goat milk origin screened in this study may serve as bio-control agents for prophylactic use to prevent infections. [ABSTRACT FROM AUTHOR]

This study was undertaken to characterize a lactic acid bacterium 4I1, isolated from the freshwater fish, Zacco koreanus. Morphological, biochemical, and molecular characterization of 4I1 revealed it to be Pediococcus pentosaceus 4I1. The cell free supernatant (CFS) of P. pentosaceus 4I1 exhibited significant (p < 0.05) antibacterial effects (inhibition zone diameters: 16.5-20.4 mm) against tested foodborne pathogenic bacteria with MIC and MBC values of 250-500 and 500-1,000 mg/mL, respectively. Further, antibacterial action of CFS of P. pentosaceus 4I1 against two selected bacteria Staphylococcus aureus KCTC-1621 and Escherichia coli O157:H7 was determined in subsequent assays. The CFS of P. pentosaceus 4I1 revealed its antibacterial action against S. aureus KCTC-1621 and E. coli O157:H7 on membrane integrity as confirmed by a reduction in cell viability, increased potassium ion release (900 and 800 mmol/L), reduced absorption at 260-nm (3.99 and 3.77 OD), and increased relative electrical conductivity (9.9 and 9.7%), respectively. Gas chromatography-mass spectrometry (GC-MS) analysis of the CFS of P. pentosaceus 4I1 resulted in the identification of seven major compounds, which included amino acids, fatty acids and organic acids. Scanning electron microscopic-based morphological analysis further confirmed the antibacterial effect of CFS of P. pentosaceus 4I1 against S. aureus KCTC-1621 and E. coli O157:H7. In addition, the CFS of P. Pentosaceus 4I1 displayed potent inhibitory effects on biofilms formation by S. aureus KCTC-1621 and E. coli O157:H7. The study indicates the CFS of P. pentosaceus 4I1 offers an alternative means of controlling foodborne pathogens. [ABSTRACT FROM AUTHOR]

In this work, 100 samples each of 'ugba' and 'okpiye' were evaluated for the presence of bacteriocin producing lactic acid bacteria. Thirty strains showing antibacterial activity against at least one of the indicator organisms were selected from a total of 752 colonies isolated from the condiments. Out of the 30, only five strains retained activity after the pH of the broth supernatant was adjusted to 6.5. When evaluated by the agar-well diffusion assay, the spectra of inhibitory activity showed that Staphylococcus aureus was the most sensitive indicator organism tested, while Listeria monocytogenes was the most resistant. One strain (UG 2) was active against Escherichia coli. The assays using the cell-free supernatant of the cultures showed that the bacteriocins were completely inactivated by the proteolyses as well as by the chloroform treatment. In ethanol, the activity of the compounds was only partially modified. When incubated in a water bath at 80°C for 30 min, no significant activity loss was recorded. The antimicrobial activity of the bacteriocins produced by the lactic acid bacteria has potential for use in biopreservation of condiments against the spoilage and food - borne pathogens.

This study investigated the antifungal activities of probiotic bacteria isolated from traditional herbal juice, which was a blend of Tulsi, Mint, Bael and Indian borage leaves. About 20 isolates were obtained from the herbal juice sample; these isolates were initially screened against fungal pathogens such as Aspergillus parasiticus , Aspergillus flavus , Aspergillus ochraceus , Aspergillus carbonarius and Aspergillus fumigatus. Of the 20 isolates obtained, MYSAGT3 and MYSAGT4 exhibited potential antifungal activity against the tested fungal pathogens. Moreover, MYSAGT3 and MYSAGT4 was found to survive acidic pH and bile conditions, but were susceptible to tested antibiotics. Both the isolates exhibited 40–60% of autoaggregation ability, >90% of cell surface hydrophobicity and tolerance to 0.4–0.6% phenol. The 16S rRNA sequencing results identified the isolates MYSAGT3 and MYSAGT4 as Lactiplantibacillus plantarum. The MYSAGT3 exhibited potent antagonistic and probiotic activity compared to MYSAGT4; hence MYSAGT3 was further used for the control of Aspergillus ochraceus. Initial antifungal activity of MYSAGT3 inhibited about 76.67% growth of Aspergillus ochraceus comparatively higher than other Aspergillus sp. tested. Co-inoculation and microdilution assay revealed the high inhibitory activity of Lactiplantibacillus plantarum MYSAGT3. Further, cell free supernatant (CFS) of Lactiplantibacillus plantarum MYSAGT3 reduced the growth of fungal hyphae and conidial germination of Aspergillus ochraceus in conidial germination assay and bio preservative activity on peanuts. The CFS characterization and Liquid chromatography-mass spectroscopy (LCMS) results showed that, the antifungal activity was due to different organic acids present in the CFS of MYSAGT3. MYSAGT3 and its CFS also reduced the growth of Aspergillus ochraceus in Poultry feeds and about 21.80% of ochratoxin A (OTA) degradation was attained after 24 h of incubation with MYSAGT3. The isolated Lactic acid bacteria are able to inhibit Aspergillus ochraceus and degrade OTA in-vitro. Hence, the results suggest Lactiplantibacillus plantarum MYSAGT3 as an efficient probiotic organism and possess antifungal properties. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) were isolated from different soil samples such as dairy, garden, rhizospheric soil and sediments of lake. Thirty nine strains of bacteria were isolated using direct spreading method but only one showed the characteristics of LAB. Whereas, using accumulation with incubation method, fifty seven strains were found to be LAB out of sixty eight strains of bacteria isolated. Therefore, accumulation with incubation method was found to be more effective and faster. On the basis of higher growth and antimicrobial activity, two potential isolates LB44 and LM85 were selected for the further characterization. Strain LB44 and LM85 were identified using 16S rDNA amplification and sequencing as Pediococcus pentosaceus LB44 and Weissella confusa LM85, respectively. Cell free supernatant (CFS) of these strains showed antimicrobial activity, stability at higher temperatures, acidic pH and in the presence of organic solvents, detergents and surfactants. Antimicrobial activity was not affected by treatment with catalase and lipase but reduced after treatment with proteinase K reveals the presence of bacteriocin-like inhibitory substance in CFS. CFS inhibited the growth of other Gram-positive and Gram-negative bacteria such as Micrococcus luteus, Lactobacillus delbrueckii, L. curvatus, L. plantarum, L. acidophilus, Enterobacter cloaceae, Lactococcus lactis subsp. cremoris, L. lactis subsp. lactis, Bacillus subtilis, B. licheniformis, Salmonella typhi and Escherichia coli. [ABSTRACT FROM AUTHOR]

• Postbiotics are a mixture of microbial-derived substances with diverse functions. • Postbiotics are produced by different food-grade microorganisms including lactic acid bacteria. • The type of instrumental technique impresses the chemical composition of postbiotics. • Any modification in culturing methods could also affect the chemical composition of postbiotics. Postbiotics may be defined as soluble metabolites released by food-grade microorganisms during the growth and fermentation in complex microbiological culture, food or gut. It is rich in high and low molecular weight biologically active metabolites. There are still gaps concerning these substances, mainly how to use them for food applications. Although the most recent work on preparation and application of postbiotics from several probiotics are very encouraging, the suitability of postbiotics to combat microorganisms that deal with food safety should be tested mainly by analyzing the chemical composition and conducting antagonistic tests. Consequently, foods can effectively benefit from an identified postbiotic with a defined effect. This review approached the recent advances in relation to the preparation of postbiotics from lactic acid bacteria. The function of different instrumental analysis techniques and factors affecting the chemical composition of postbiotics were also comprehensively reviewed. [ABSTRACT FROM AUTHOR]