Nutrition And Food In Health And Disease

en Molecular Identification of Lactobacillus acidophilus Strain ABC240 Isolated from Traditional Yogurt and Assessing Its Stability and Safety as well as Antibacterial and Antioxidant Activities Food Science Food Science پژوهشي Research 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. Dairy fermentation products, Probiotic characteristics, Antimicrobial activity, Biogenic amines 31 39 http://nfsr.sbmu.ac.ir/browse.php?a_code=A-10-542-6&slc_lang=en&sid=1 Behrooz Alizadeh Behbahani behrooz66behbahani@gmail.com 10031947532846006693 10031947532846006693 Yes Department of Food Science and Technology, Faculty of Animal Science and Food Technology, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran Hossein Hossein Jooyandeh hosjooy@yahoo.com 10031947532846006694 10031947532846006694 No Department of Food Science and Technology, Faculty of Animal Science and Food Technology, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran Heidar Rafiee rafiee.elmi@gmail.com 10031947532846006695 10031947532846006695 No Department of Food Science and Technology, Faculty of Animal Science and Food Technology, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran