Antibacterial activity of Lactobacillus delbreukii subspecies bulgaricus isolated from Zabady

negm, sally and Al-Mohammadi, Abdul-Raouf and Enan, Gamal and Abdel-Shafi, Seham (2014) Antibacterial activity of Lactobacillus delbreukii subspecies bulgaricus isolated from Zabady. life science, 11 (8). pp. 264-270. ISSN 1097-8135

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Abstract: Lactic acid bacteria are used recently as probiotics and as protective cultures in fermented food products. This is due to their ability to produce proteinacous antimicrobial agents, lactic acid and diacetyle. The prime objective of this work was to select a probiotic bacterium which could be used as protective culture. Characterization of bacteriocin by physicochemical techniques and inhibition of food-borne pathogens were carried out. Molecular methods were used for identification of bacterial strains used. Out of 100 lactic acid bacterial strains, the most inhibitory strain (Z55 strain) isolated from Arabian yoghurt (Zabady) inhibited other lactic and bacteria and some food-borne pathogens. This Z55 strain was identified as Lactobacillus delbreukii subspecies bulgaricus and designated Lb. bulgaricus Z55. The inhibitory activity of cell free supernatant (CFS) of Lb. bulgaricus Z55 was lost by proteolytic enzymes, heat resistant. Consequently it was characterized as a bacteriocin. This bacteriocin was shown to consists of protein but has no lipidic or glucidic moieties in its active molecule. Its activity was stable in the pH range 2.0 to 7.0. Maximum bacteriocin production was obtained in MRS broth adjusted initially at pH 6.5 and incubated for 18 h at 350 C when the producer organism was in the late logarithmic and early stationary phase of growth. A bacteriocin producer strain (Lb. bulgaricus Z55) inhibited many food-borne pathogens. The antimicrobial agent was showed to be protein and characterized as a bacteriocin

Item Type|تصنيف النتاج العلمي: Article| منشور علمي
Subjects | مجال موضوع النشر: Medical laboratory
Divisions | الكلية: College of Applied Medical Sciences - Mahyal Aseer > Nursing
Depositing User: Sally Nasr
Date Deposited: 23 Jan 2019 07:03
Last Modified: 23 Jan 2019 07:03

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