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Abstract Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC’s swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC–MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.

• Isolation of Limosilactobacillus sp. MYSN3 isolated from noni fruit (Morinda citrifolia). • Limosilactobacillus sp. MYSN3 CFS showed 69.98, 63.60 and 69.12 % inhibition of R. solanacearum, X. oryzae pv. oryzae and P. carotovorum sub sp. carotovorum respectively in microplate assay. • Limosilactobacillus sp. MYSN3 was effective in phosphorous, potassium, zinc, silicon solubilization, IAA and GA 3 production along with siderophore production and protease activity and enhanced growth of tomato, chilli and okra plants under glasshouse condition. The aim of the study was to determine the antibacterial, plant growth promotion and bio-control activity of Limosilactobacillus sp. MYSN3 isolated from noni fruit (Morinda citrifolia). The noni fruit yielded eight distinct isolates and one effective isolate MYSN3 was chosen considering their antibacterial activity for further studies. The isolate MYSN3 recorded good inhibitory effect toward the tested plant pathogenic bacteria. The CFS of MYSN3 showed 69.12, 69.98 and 63.60 % inhibition against, Pectobacterium carotovorum sub sp. carotovorum, Ralstonia solanacearum and Xanthomonas oryzae pv. oryzae respectively in microplate assay. The isolate MYSN3 was identified as Limosilactobacillus sp. with accession number OL347895 and was verified using 16sRNA gene sequencing and had 95.23 % similarity with the earlier deposited sequence of Limosilactobacillus sp. - KJ865402. The effective isolate MYSN3 was characterized for growth promotion in plants and biological control attributes. Isolate MYSN3 showed IAA production (35.18 µg/ml), gibberellic acid production (23.45 µg/ml), solubilization of phosphate, potash, zinc and silicon and gave positive outcomes for protease and siderophore production and negative for cellulose degradation activity, HCN production activity and amylase activity. Seed treatment with Limosilactobacillus sp. MYSN3 greatly enhanced the standard of seed germination and seedling vigour of tomato by paper towel method and significantly increased plant height of tomato, chilli and okra under glasshouse condition when compared to control. The findings of the current research revealed that isolated Limosilactobacillus sp. MYSN3 possess promising antibacterial activity, plant growth promoting characteristics and bio-control traits. The potentiality of the isolate as bioinoculants and bio-control agents deserves further investigation. [ABSTRACT FROM AUTHOR]

In this investigation, Blue Cherry fruit was used to isolate potential probiotic isolate and characterized for their beneficial attributes. The main objective of the study was to evaluate the antagonistic activity of the isolated bacteria against plant pathogenic bacteria such as Ralstonia solanacearum, Pectobacterium carotovorum sub sp. carotovorum and Xanthomonas oryzae pv oryzae and also to evaluate the isolate for potential probiotic, plant growth promoting and biocontrol activity. A total of nine isolates were isolated from Blue Cherry fruit and initially screened for microscopic and biochemical characters. The agar-well diffusion method, paper disc, spot inoculation and microplate method were used to test the antibacterial activity from the cultured supernatants against plant pathogenic bacteria and zone of inhibition ranged from 0.6 to 2.1 cm and per cent inhibition of plant pathogenic bacteria ranged from 64.81 to 71.70 %. Effective isolate MYSBC14 was genotyped based on 16S rDNA and identified as Enterobacter faecium OL454757. Effective isolate E. faecium MYSBC14 was further characterized for probiotic properties, PGPR and bio-control attributes. MYSBC14 survived under pH 2 and pH 4 after 2 and 4 h after incubation (38.08 and 23.16 %, 87.90 to 82.02 % respectively) and was susceptible to majority of antibiotics evaluated. A survival rate of 52.67 and 43.01 % was recorded at 0.3 % oxgall salt concentration after 2 and 4 h after incubation. The cell surface hydrophobicity of 90.24 % and auto aggregation of 8.10 to 22.02 % represented the adhesion properties of the isolate. MYSBC14 showed indole acetic acid production (11.56 µg/mL), gibberellic acid production (10.18 µg/mL) and gave positive results for solubilization of phosphate, potash, protease and siderophore production and was found negative for zinc and silicon solubilization, cellulose degradation activity, HCN production activity and amylase activity. The findings of the present investigation showed that isolated probiotic organism possesses promising antibacterial, probiotic attributes, plant growth promoting characteristics and bio-control traits.

Abstract Background Probiotics and their derived postbiotics, as cell-free supernatants (CFS), are gaining a solid reputation owing to their prodigious health-promoting effects. Probiotics play a valuable role in the alleviation of various diseases among which are infectious diseases and inflammatory disorders. In this study, three probiotic strains, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Pediococcus acidilactici, were isolated from marketed dietary supplements. The antimicrobial activity of the isolated probiotic strains as well as their CFS was investigated. The neutralized CFS of the isolated probiotics were tested for their antibiofilm potential. The anti-inflammatory activity of the isolated Lactobacillus spp., together with their CFS, was studied in the carrageenan-induced rat paw edema model in male Wistar rats. To the best of our knowledge, such a model was not previously experimented to evaluate the anti-inflammatory activity of the CFS of probiotics. The histopathological investigation was implemented to assess the anti-inflammatory prospect of the isolated L. plantarum and L. rhamnosus strains as well as their CFS. Results The whole viable probiotics and their CFS showed variable growth inhibition of the tested indicator strains using the agar overlay method and the microtiter plate assay, respectively. When tested for virulence factors, the probiotic strains were non-hemolytic lacking both deoxyribonuclease and gelatinase enzymes. However, five antibiotic resistance genes, blaZ, ermB, aac(6’)- aph(2”), aph(3’’)-III, and vanX, were detected in all isolates. The neutralized CFS of the isolated probiotics exhibited an antibiofilm effect as assessed by the crystal violet assay. This effect was manifested by hindering the biofilm formation of the tested Staphylococcus aureus and Pseudomonas aeruginosa clinical isolates in addition to P. aeruginosa PAO1 strain. Generally, the cell cultures of the two tested probiotics moderately suppressed the acute inflammation induced by carrageenan compared to indomethacin. Additionally, the studied CFS relatively reduced the inflammatory changes compared to the inflammation control group but less than that observed in the case of the probiotic cultures treated groups. Conclusions The tested probiotics, along with their CFS, showed promising antimicrobial and anti-inflammatory activities. Thus, their safety and their potential use as biotherapeutics for bacterial infections and inflammatory conditions are worthy of further investigation.

Background: Probiotics and their derived postbiotics, as cell-free supernatants (CFS), are gaining a solid reputation owing to their prodigious health-promoting effects. Probiotics play a valuable role in the alleviation of various diseases among which are infectious diseases and inflammatory disorders. In this study, three probiotic strains, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Pediococcus acidilactici, were isolated from marketed dietary supplements. The antimicrobial activity of the isolated probiotic strains as well as their CFS was investigated. The neutralized CFS of the isolated probiotics were tested for their antibiofilm potential. The anti-inflammatory activity of the isolated Lactobacillus spp., together with their CFS, was studied in the carrageenan-induced rat paw edema model in male Wistar rats. To the best of our knowledge, such a model was not previously experimented to evaluate the anti-inflammatory activity of the CFS of probiotics. The histopathological investigation was implemented to assess the anti-inflammatory prospect of the isolated L. plantarum and L. rhamnosus strains as well as their CFS. Results: The whole viable probiotics and their CFS showed variable growth inhibition of the tested indicator strains using the agar overlay method and the microtiter plate assay, respectively. When tested for virulence factors, the probiotic strains were non-hemolytic lacking both deoxyribonuclease and gelatinase enzymes. However, five antibiotic resistance genes, blaZ, ermB, aac(6')- aph(2"), aph(3")-III, and vanX, were detected in all isolates. The neutralized CFS of the isolated probiotics exhibited an antibiofilm effect as assessed by the crystal violet assay. This effect was manifested by hindering the biofilm formation of the tested Staphylococcus aureus and Pseudomonas aeruginosa clinical isolates in addition to P. aeruginosa PAO1 strain. Generally, the cell cultures of the two tested probiotics moderately suppressed the acute inflammation induced by carrageenan compared to indomethacin. Additionally, the studied CFS relatively reduced the inflammatory changes compared to the inflammation control group but less than that observed in the case of the probiotic cultures treated groups. Conclusions: The tested probiotics, along with their CFS, showed promising antimicrobial and anti-inflammatory activities. Thus, their safety and their potential use as biotherapeutics for bacterial infections and inflammatory conditions are worthy of further investigation. [ABSTRACT FROM AUTHOR]

Lactobacillus rhamnosus SD11 is a probiotic derived from the human oral cavity and has potential being used for dental prophylaxis. The cell free supernatant (CFS) of L. rhamnosus SD11 has good antimicrobial and antioxidant effects. This study aimed to incorporate CFS of the probiotic into thermoresponsive copolymers to create a sol–gel formulation. The sol–gel formulation was developed using Poloxamer 407 as the main polymer, which was mixed with natural polymers such as gellan gum, sodium alginate, and xyloglucan in different proportions. The sol–gel formulations were characterized based on their physicochemical parameters such as appearance, pH, viscosity, flow-ability in low temperature, antioxidant and antibacterial activity. An in vitro release study was performed using Franz's diffusion cell and the stability was determined under freeze-thaw cycle conditions. The combination of 15% w/v of poloxamer 407 with 0.5% w/v of sodium alginate was the best sol–gel formulation to deliver the CFS of the probiotic. This study was successful in creating a sol–gel formulation using a thermoresponsive copolymer, that could efficiently deliver CFS of the probiotic L. rhamnosus SD11. [ABSTRACT FROM AUTHOR]

• 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]

Background Lactobacillus rhamnosus SD11 is a probiotic derived from the human oral cavity and has potential being used for dental prophylaxis. The cell free supernatant (CFS) of L. rhamnosus SD11 has good antimicrobial and antioxidant effects. Aim This study aimed to incorporate CFS of the probiotic into thermoresponsive copolymers to create a sol–gel formulation. Methods The sol–gel formulation was developed using Poloxamer 407 as the main polymer, which was mixed with natural polymers such as gellan gum, sodium alginate, and xyloglucan in different proportions. The sol–gel formulations were characterized based on their physicochemical parameters such as appearance, pH, viscosity, flow-ability in low temperature, antioxidant and antibacterial activity. An in vitro release study was performed using Franz’s diffusion cell and the stability was determined under freeze-thaw cycle conditions. Results The combination of 15% w/v of poloxamer 407 with 0.5% w/v of sodium alginate was the best sol–gel formulation to deliver the CFS of the probiotic. Conclusion This study was successful in creating a sol–gel formulation using a thermoresponsive copolymer, that could efficiently deliver CFS of the probiotic L. rhamnosus SD11.

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]

The purpose of this study was to investigate the potential probiotic properties, gene expression related to biofilm formation, and anti-biofilm capabilities of Lacticaseibacillus rhamnosus CWKu-12. This strain showed notable resistance to acidic conditions, gastrointestinal environments, and bile salts. Additionally, L. rhamnosus displayed significant levels of auto-aggregation (36.60%), hydrophobicity (52.60%), co-aggregation (29.10%), free radical scavenging activities (55–59%), and cholesterol reduction (49.30%). Its ability to compete with, replace, and hinder the adhesion of Listeria monocytogenes was measured at 41.70%, 22.60%, and 30.54% respectively. L. rhamnosus also showed an adhesion rate of 11.80% to epithelial cells, did not exhibit DNase or hemolytic activity. It was susceptible to the antibiotics ciprofloxacin, erythromycin, and chloramphenicol and semi-susceptible to ampicillin, imipenem, nitrofurantoin, and nalidixic acid. The strain's cell free supernatant (CFS) effectively inhibited and eliminated L. monocytogenes biofilm formation, with inhibitory rates of 44.30% and eradication rate of 38.70%. Treatment with CFS also led to a significant decrease in the expression of various genes related to L. monocytogenes by percentages ranging from 35.54% to 79.80%. Overall, these findings support the potential of L. rhamnosus CWKu-12 as a probiotic, with its ability to survive in the digestive system, and combat harmful bacteria making it a promising candidate. • Lacticaseibacillus rhamnosus CWKu-12 shows promise as a probiotic candidate. • The cell free supernatant (CFS) of L. rhamnosus effectively inhibits biofilm formation in L. monocytogenes. • CFS represses the expression of virulence genes in L. monocytogenes. [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 negative effects of more extreme pH conditions (soil acidity and alkalinity) are increasingly challenging crop production. Managing acidity and alkalinity in soils has been achieved through techniques such as the use of lime, afforestation, tillage, and addition of organic matter. The use of microbes to address this challenge is new and could increase agroecosystem sustainability while helping plants survive more extreme acidity and alkalinity, among other stresses. Use of plant growth promoting microbes (PGPM) has recently gained attention as these microbes afford plants several benefits, including nutrient acquisition and stress tolerance, both biotic and abiotic. Several methods of microbe application have been developed, all intended to maximize the benefits of plant-microbial interactions. The current study assessed the potential of changing microbial culture pH during production, followed by removal of cells to produce supernatant that enhances plant growth, specifically under acidity and alkalinity stresses. The study included L. helveticus. (EL2006H) and B. subtilis (EB2004S) which were cultured at three pH levels (5, 7, and 8) incubated for 24–48 h then centrifuged at 12 000 g to remove the cells. The cell-free supernatants obtained were used for seed germination and early seedling growth assays. The results indicated significant increase in seed germination rate, for both corn and tomato, compared to experimental controls. Supernatants produced at pH 5, for both strains, had greater effect than those produced at pHs 7 and 8. Similarly, the positive effect of these supernatants was observed in seedling growth as increased root length and volume. Their results indicate that there is potential in stressing microbes below or above optimum pH (~7) to induce production and excretion of favorable materials into the growth medium, as was evident in this study. To the best of our knowledge this would be the first attempt to look at this pH change to increase potential benefits related to plant growth promotion by microbes. It was interesting to learn that using the CFS of microbes cultured at pH 5 increased germination rate and seedling growth. These results provide an initial indication that support broadened research into PGPM under pH stressed conditions.

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Biogenics are compounds produced by living organisms such as animals, plants, bacteria, etc. Probiotics and their biogenics are known for their antimicrobial potential. Therefore, the present study was designed to evaluate the antibiofilm potential of probiotic-derived biogenics in conjunction with zingerone against the Pseudomonas aeruginosa PAO1 biofilm. Cell-free supernatant (CFS) of potential probiotics Pediococcus acidilactici BNS5B and Lactobacillus fermentum PUM was found to inhibit the growth of Ps. aeruginosa PAO1 maximally among the nineteen isolated lactic acid bacteria. L. fermentum PUM produced precipitated protein fraction (PP), organic acids (OAs), exopolysaccharides (EPSs), biosurfactants (BSs) and various volatile antimicrobial compounds, while Ped. acidilactici BNS5B was found to produce PP, OA, EPS, BS and fewer volatile antimicrobial compounds only. More specifically, CFS and selected biogenics (OA and PP from L. fermentum PUM; OA from Ped. acidilactici BNS5B) of both potential probiotics showed synergy with zingerone against Ps. aeruginosa growth as observed by FIC index (< 0.5). Interestingly, CFS of both potential probiotics in combination with zingerone led to the formation of a more distorted biofilm compared with OA of L. fermentum PUM and zingerone, OA of Ped. acidilactici BNS5B and zingerone, PP of L. fermentum PUM and zingerone as well as their individual counterparts. Similarly, both confocal laser scanning microscopy and XTT assay showed an increased number of dead and impaired cells along with the decreased viability of biofilm cells. Thus, it can be reckoned that a combination of probiotic-derived biogenics and zingerone can have therapeutic application against Ps. aeruginosa infections which needs to be validated clinically. [ABSTRACT FROM AUTHOR]

Bacterial spot is a disease that affects tomato worldwide reducing its yield and quality. It is caused by different Xanthomonas spp., among which is Xanthomonas vesicatoria. Copper-based bactericides are generally used to control this disease, although nowadays sustainable strategies are being searched to efficiently replace their use. Our aim was to select native bacteria from tomato rhizosphere with biocontrol properties against X. vesicatoria. We selected, characterized, and identified three novel strains, two closely related to Bacillus velezensis (VMA11p and VM05) and one closely related to Pseudomonas soli (VMAP1), that in vitro antagonized X. vesicatoria. We evaluated the efficacy of the three rhizobacteria and their cell-free supernatants to control bacterial spot using the model tomato-X. vesicatoria in plants grown in pots, in greenhouse conditions. Bacterial suspensions of VMA11p and VMAP1, applied to the soil by irrigation, significantly (P < 0.05) reduced bacterial spot severity by 53.9% and 44.2%, respectively. Nevertheless, the most effective strategy to control bacterial spot was achieved using the cell-free supernatant produced by VMA11p, VM05 or VMAP1 applied as foliar spray, which significantly (P < 0.05) reduced the severity of the disease by 98.5%, 94.2% and 75.2%, respectively. None of the treatments reduced the growth of tomato plants. Our results suggest that the use of these novel strains of Bacillus and Pseudomonas and/or their metabolic products could be used for the development of biocontrol strategies for the management of bacterial spot in tomato. [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.

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]

Ginseng ( Panax ginseng Meyer) is a perennial medicinal plant. Long cultivation practice makes ginseng vulnerable to attack by various biotic constrains. The biocontrol of ginseng pathogens with microbes is an important alternative to chemical control. We screened 252 bacterial endophytes isolated from mountain-cultivated ginseng against 6 ginseng pathogens. Twelve bacterial endophytes were selected using a dual culture assay. Overall, Burkholderia stabilis EB159 (PG159) exerted the greatest inhibitory activity against all ginseng pathogens (42.3–84.7% inhibition). Cell-free supernatant and ethyl acetate extracts of PG159 exerted significant antagonistic effects against all pathogens (37.3–100 and 30.6–100%, respectively). Direct treatment of Botrytis cinerea with PG159 cell-free supernatant down-regulated pathogen genes involved in growth and virulence ( BCG1 , BOT1 , PKA1 and TRE1 ). Direct inoculation of ginseng roots with PG159 by dipping induced genes involved in defense, either in above- or below-ground parts of ginseng plants ( PR2 , PR3 , PR4 , PR5 , PR6 and PR10 ). B. cinerea genes involved in growth ( BCG1 , BAC , PKA1 , CHS3 and TRE1 ) were also down-regulated in PG159 pre-inoculated plants. PG159 inoculation significantly reduced the disease area induced by B. cinerea in ginseng leaves. [ABSTRACT FROM AUTHOR]

The aim of the work is to assess the antimicrobial activities of Cell Free Supernatants (CFS) and Membrane Vesicles (MVs), produced by Lactobacillus reuteri DSM 17938, versus Gram-positive and Gram-negative bacteria and investigate their metabolic profiles. The Minimum Inhibitory Concentration was determined through the broth microdilution method and cell proliferation assay while the Minimum Bactericidal Concentration was determined by Colony Forming Units counts. The characteristics of the antimicrobial compounds were evaluated by pH adjustments, proteinase treatment, and size fractionation of the CFS. The cytotoxicity of CFS was tested on two human cell lines. A detailed snapshot of the L. reuteri metabolism was attained through an untargeted metabolic profiling by means of high resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) coupled with Electrospray Ionization Source (ESI). The results showed (i) a greater efficacy of CFS and its fractions towards Gram-negative compared to Gram-positive bacteria; (ii) an antimicrobial effect related to pH-dependent compounds but not to MVs; (iii) a molecular weight < 3 KDa as well as an a non-proteinaceous nature of the antimicrobial compounds; and (iv) more than 200 and 500 putative metabolites annotated in MVs and supernatants, covering several classes of metabolites, including amino acids, lipids, fatty and organic acids, polyalcohols, nucleotides, and vitamins. Some putative compounds were proposed not only as characteristic of specific fractions, but also possibly involved in antimicrobial activity.

The enterovirus Coxsackievirus B4 (CV-B4) can infect different human tissues and provoke abnormal function or destruction of various organs and cells. Moreover, its infections have been linked to the onset of type 1 diabetes. Coxsackievirus B4 is classified as a “challenging virus”, due to the intense yet vain efforts to find effective prevention and therapeutic agents, especially within biological compounds. Lactobacillus plantarum is a lactic acid bacterium that is endowed with probiotic properties, and holds great potential for applications in medical and food industry sectors. Several compounds produced by this microorganism have been associated with various benefits including antimicrobial activity. In this work, we investigated the possible antiviral abilities of two Lb. plantarum strains and their derivatives against CV-B4. The different assays carried out (e.g. pre-incubation, competition and post-infection, using HEp-2 cells as human cell model) suggest that the tested microorganisms and their derivatives have an in vitro inhibiting activity against CV-B4. This is the first report showing the anti-CVB4 activity of Lb. plantarum strains and their derivatives. [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]

The aim of the present study was to evaluate the dietary administration of Bacillus aerophilus KADR3 on enhancing the immunity and disease resistance against Aeromonas hydrophila infection in Labeo rohita . B. aerophilus culture supernatant exhibited antagonistic activity against fish pathogenic bacteria in an agar well diffusion assay. Four fish groups were fed with either of following diets containing different concentrations of B. aerophilus KADR3 (cfu g −1 ): 0 (control), 1 × 10 7 (DI), 1 × 10 8 (DII), and 1 × 10 9 (DIII) –cfu g −1 . Various innate immune parameters were measured at – 3rd and 6th – week post-feeding. At the end of 6th week, fish were challenged intraperitoneally with A. hydrophila and survival percentage was recorded over 10 days post-challenge. Studied immunological parameters viz. serum lysozyme, phagocytosis, serum total protein, respiratory bursts, serum IgM levels, superoxide dismutase and alternative complement pathway activities were significantly enhanced ( P < 0.05) in fish groups fed with B. aerophilus KADR3 supplemented diets, with the highest values were observed in DII (10 8 cfu g −1 ) fed group. Further, B. aerophilus supplementation at 10 8 cfu g −1 exhibited highest post-challenge survivability i.e. 72.83%, followed by DIII (64.19%) and DI (41.97%). Our results collectively suggest that B. aerophilus can potentially be used as probiotic strain in aquaculture to enhance the immunity and disease resistance with an optimal dietary supplementation of 10 8 cfu g −1 . [ABSTRACT FROM AUTHOR]

Autochthonous endosymbiotic gut bacteria antagonistic against pathogenic Aeromonas spp. have been evaluated in rohu, Labeo rohita for characterization of putative probiotics. Four promising pathogen inhibitory bacteria (23 strains out of 225 isolates showed antagonism) were selected by double layer assay, following which inhibition pattern was examined through in vitro growth curve and statistical analyses. Cell free supernatant (CFS) of the selected gut bacteria significantly inhibited the growth of pathogenic aeromonads. While, CFS of strain LR3FG26 was the most efficient among them. Selected strains were γ haemolytic and susceptible to most of the common antibiotics that demonstrated their likely non-pathogenic and eco-friendly nature. Additionally, selected bacteria produced different exo-enzymes (digestive and antinutritional factors degrading), could grow better in skin mucus than intestinal mucus (exceptionally, LR3FG26 grew better in skin mucus) and tolerated diluted bile juice (2-20%). 16S rRNA partial gene sequence analyses and Blast search in NCBI GenBank unveiled that the strains LR1FG1, LR2HG13, LR3FG26 and LR3HG4 were similar with the type strains of Bacillus methylotrophicus (NR116240), Bacillus amyloliquefaciens (NR117946), Pseudomonas fluorescens (NR113647) and Bacillus licheniformis (NR118996), respectively. Application of these symbiotic pathogen-inhibitory bacteria in pathogen challenge studies is required to appraise their probiotic effects in vivo. [ABSTRACT FROM AUTHOR]

Sclerotium rolfsii is a broad host necrotrophic pathogen causing serious damages in crop yields. Apart from chemical fungicides being used to control this pathogen, no bio-fungicides have been reported till date. In this study, we have tried to utilize heat killed S. rolfsii hyphae for triggering biosynthesis of antifungal compounds in the endophytic bacterium Alcaligenes faecalis BHU 12. The endophytic bacterial cell free supernatant (CFS) obtained by growing BHU 12 in presence of freeze-crushed and autoclaved S. rolfsii hyphae caused prominent S. rolfsii hyphal degeneration and inhibition of sclerotial germination under in vitro conditions. This result was further corroborated under in planta conditions wherein spraying of the CFS at the point of infection inhibited further pathogen ingress. This observation was justified by the presence of gallic and shikimic acid in the CFS which served as antifungal agent and augmentor of plant defense system respectively. Infected plants sprayed with the CFS were found to display a prominent increase in phenylalanine ammonia lyase activity and a corresponding increase in total phenolics. In this context, our results described the possible alternative of using endophytic bacterial metabolite compounds as biofungicides. A simultaneous augmentation in seed germination upon treatment with the CFS suggests a possibility of using endophytic bacterial supernatants as biocontrol and biofertilizer alternative instead of whole bacterial cell since indigenous soil microbiota combined with cumbersome inoculation techniques prevents successful colonization of endophytic microbes in planta. • Killed S. rolfsii induces production of antifungal products in A. faecalis extract. • The extract causes hyphal and sclerotial damage under in vitro conditions. • Prominent inhibition of S. rolfsii growth in planta treated with A. faecalis extract. • Upregulation of plant defense enzymes upon treatment with A. faecalis extract. [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

In view of emerging drug resistance in pathogens, there is a need to explore alternative strategies to combat infections. Use of probiotics is one such option. In this regard, efficacy of Lactobacillus plantarum has been reported against Staphylococcus aureus. Here, we propose that cell free supernatant (CFS) of Lactobacillus paraplantarum when used in combination with conventional antibiotics viz. ampicillin and oxacillin [to which the methicillin resistant Staphylococcus aureus (MRSA) strains were originally resistant] reduce the minimum inhibitory concentrations of these antibiotics, rendering the combination either synergistic or additive against the tested MRSA strain. The anti-staphylococcal activity was observed to be due to organic acids (acetic acid and lactic acid as confirmed by HPLC analysis) present in the CFS, as neutralization of the CFS with an alkali, sodium hydroxide (NaOH), caused the complete abrogation of its activity. The role of HO and bacteriocin present in the CFS was also ruled out. The findings of this study suggest that cell free supernatant and ampicillin/oxacillin combination(s) might help in rejuvenating the use of conventional anti-staphylococcal antibiotics for the treatment of multi-drug resistant strains. [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]

Lactic acid bacteria (LAB) play essential role in production of fermented food, being a part of natural microbiota of milk. With their metabolic activity they influence the ripening process of milk, allowing the creation of desirable sensory qualities of the product, while inhibiting the growth of undesirable microorganisms. As a by-product of their metabolism, lactic acid bacteria produce a variety of substances with antimicrobial activity such as organic acids (lactic and acetic acid), hydrogen peroxide, ethanol, diacetyl and bacteriocins. Bacteriocins are antimicrobial peptides or proteins with bactericidal activity on certain microorganisms. In this study, cell free supernatant was isolated from lactic acid bacteria of domestically produced fresh cow cheese. This kind of cheese was produced in traditional way, in households of Tuzla Canton, without adding any starter cultures. Isolation and characterization of LAB found that natural microflora of domestically produced cheese was consisted of bacteria of Lactobacillus and Lactococcus species. Concentrated samples of cell free supernatant were isolated out of ten characterized strains, and their antimicrobial activity was tested against pathogenic bacteria Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Salmonella enteritidis. The highest inhibitory activity on the growth of pathogenic bacteria showed cell free supernatant isolated from Lactobacillus plantarum 1 and Lactobacillus brevis 1. Sensitivity of the supernatant to proteolytic enzyme was tested by using proteinase K. After exposure of the supernatants to proteinase K, the results showed a significant reduction of inhibitory effect. The results proved the protein structure of the cell free supernatant, or the possible presence of bacteriocins and their bacteriocinogenic activity. [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]

Biosynthesis of gold nanoparticles was investigated usingAspergillus flavusand the procedure was optimized for maximum production. The color changing from whitish-yellow to purple along with the maximum absorbance at 540 nm in UV-vis spectrum approved the production of gold nanoparticles preliminarily. The XRD spectrum of nanoparticles showed 2θ values corresponding to the gold nanocrystals. TEM micrographs demonstrated the extracellular formation of spherical gold nanoparticles. The optimization process revealed that the maximum rate of gold nanoparticles production achieved after 6 h at 28°C, 2.5 mM HAuCl4concentration, and pH 6 with different shapes in the size range of 30–50 nm. [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]