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Showing 2 results for Biogenic Amine
Zahra Kardooni, Behrooz Alizadeh Behbahani, Hossein Jooyandeh, Mohammad Noshad,
Volume 10, Issue 1 (3-2023)
Abstract
Background and Objectives: The aim of this study was to assess protection mechanisms against Escherichia coli by analyzing aggregation, adherence, antagonistic activity and safety characteristics of potentially probiotic Lactobacillus acidophilus B103.
Materials and Methods: Potentially probiotic L. acidophilus B103 has been investigated in various aspects. Studied key characteristics included its pH and bile resistance, cell surface hydrophobicity and aggregation, cholesterol removal ability, hydroxyl radical scavenging activity and adhesion ability to Caco-2 cell monolayers. Antagonistic activity of the strain was assessed by adhesion competition on E. coli via competition, inhibition and replacement assays. Moreover, safety characteristics were investigated through DNase, hemolytic activity, biogenic amine production and antibiotic susceptibility assays.
Results: L. acidophilus B103 included high stability to acidic pH (2.5 and 4.5), simulated gastric and intestinal juices and bile salt concentrations (up to 5% w/v). Moreover, L. acidophilus B103 showed relatively high hydrophobicity (51.79%), auto-aggregation (42.38%), co-aggregation (34.48%), cholesterol removal (46.27%) and hydroxyl radical scavenging activities (51.36%). Competition, replacement and inhibition anti-adhesion assays of the strain against E. coli were 52.13, 25.20 and 46.40%, respectively. Furthermore, L. acidophilus B103 adhered to simulated epithelial cells with a capacity of 11.85%. Neither DNase nor hemolytic activity was observed in the bacterial strain and the strain was highly sensitive to ciprofloxacin.
Conclusions: Based on the results, safety assessments and its food origin, L. acidophilus B103 demonstrates potential for use in the food industry. It can serve as starter culture, co-culture and bio-protective agent, effectively enhancing safety and quality of the food products.
Behrooz Alizadeh Behbahani, Hossein Hossein Jooyandeh, Heidar Rafiee,
Volume 11, Issue 4 (11-2024)
Abstract
Background and Objectives: In recent years, research has focused on the isolation of new bacterial strains with diverse and beneficially biological activities. This study investigated stability (under various acid concentrations, various bile-salt concentrations, cholesterol absorption ability and surface hydrophobicity) and antagonistic, antioxidant and immune activities of Lactobacillus acidophilus strain ABC240 isolated from traditional yogurts.
Materials and Methods: Strain was identified using polymerase chain reaction technique. Its viability was assessed under acidic conditions (pH values of 3, 4 and 5) and in presence of bile salts (concentrations of 0.3, 0.5 and 0.7%). Additionally, antimicrobial activity was assessed through well diffusion and disc diffusion methods. Antioxidant capacity was assessed using ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. This study analyzed the microbial cell surface hydrophobicity, cholesterol absorption ability and safety parameters, including antibiotic sensitivity, hemolytic activity, DNase activity and biogenic amine production.
Results: Results demonstrated high stability of this strain against various concentrations of acid (pH values of 3, 4 and 5) and bile salts (0.3, 0.5 and 0.7%). Ability of Lactobacillus acidophilus strain ABC240 to absorb cholesterol included 43.60% ±0.66 and its cell surface hydrophobicity was assessed at 50.49% ±0.63. The antimicrobial potential assessments revealed strong activity against several bacterial species. Furthermore, antioxidant activities, assessed using DPPH and ABTS methods, were detected as 44.69% ±0.89 and 49.80% ±0.79, respectively, indicating the bacterial high potential in inhibiting free radicals. Antibiotic sensitivity assay showed a non-growth zone diameter ranging from 13.20 mm ±0.55 (vancomycin) to 24.50 mm ±0.66 (chloramphenicol). Lactobacillus acidophilus strain ABC240 showed no hemolytic or DNase activity and did not produce biogenic amines.
Conclusions: In conclusion, Lactobacillus acidophilus strain ABC240 can be introduced as a new probiotic strain with biological and functional characteristics appropriate for use in the food industry.
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