Antimicrobial Activities of Lactic Acid Bacteria Strains Isolated from Burkina Faso Fermented Milk
ABSTRACT Eight strains of lactic acid bacteria producing bacteriocin were isolated from Burkina Faso fermented milk samples. These strains were identified to species: Lactobacillus fermentum, Pediococcus spp., Leuconostoc mesenteroides subsp. meseteroides, Lactococcus. Isolated bacteriocin exhibited antibacterial activity against Enterococcus faecalis 103907 CIP, Bacillus cereus 13569 LMG, Staphylococcus aureus ATCC 25293, Escherichia coli 105182 CIP using the agar drop diffusion test. The inhibition diameters obtained with bacteriocin are between 8 mm and 12 mm. Gram-positive indicator bacteria were most inhibited. The activities of the bacteriocin were lost after treatment with all the proteolytic enzymes (alpha-chymotrypsin, trypsin, pesin), whereas treatment with lipase, catalase, alpha-amylase did not affect the activity of the bacteriocin.
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ABSTRACT: Bacteriocins are proteneceous toxin produced by bacteria to inhibit the growth of similar or closely related bacteria. Among lactic acid bacteria bacteriocins are produced by Streptococcus, E.coli, Pediococcus, Pseudomonas, Carnobacterium, Enterococcus, and Staphylococcus. Bacteriocins are classified by various methods such as method of killing, genetic, molecular weight and method of production. As there are many more applications of bacteriocins in various industries such as food, pharmaceutical, cattle and poultry feed industry etc. besides this one more important application of bacteriocins is, it can be used as antimicrobial film for packaging of food items. The antimicrobial film is prepared by incorporation of antimicrobial substances into the extruder when the film or the co – extruded film is produced.
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ABSTRACT: The aim of this experiment was to isolate and identify Lactic Acid Bacteria (LAB) from infant faeces and subsequent evaluation of its potential probiotics. LAB was isolated from faeces of infants who consumed breast milk as the only source of diet on L-cysteine-supplemented MRS Agar, and incubated on 37oC for 48 hours. Colonies grew on this media were then identified based on morphological, physiological and molecular approaches. Morphological and physiological identifi cations based on Gram staining, shape, motility, spore formation, catalase, CO2 and NH3 production, and the ability to grow on temperature at 10oC and 45oC. Molecular identification based on the amplification of 16S rRNA gene. The potential application of selected isolates for probiotics was evaluated based on the ability to grow on media with low pH and the addition of 0.5% bile salts, the ability to inhibit the growth of pathogenic Bacillus cereus and Eschericia coli, and in vitro adherence ability. On the basis of morphological, physiological and molecular analysis of 16S rRNA gene, it was concluded that the selected isolate 1AF was a strain of Lactobacillus casei. Evaluation of probiotic in vitro showed that 60.4% of cells were resistant to pH 2.0 for 90 minutes. Survival of isolate 1AF after growing at 0.5% bile salts was 70.8%. The selected isolate 1AF showed the ability to inhibit the growth of Eschericia coli and Bacillus cereus with inhibitory zone of 12.00±1,00 and 15.33±1.53 mm, respectively. In vitro study on the adherence value of isolate to solid plate was found at 46.5%. It is concluded that Lactobacillus casei isolate 1AF is a potential candidate as probiotics and subject to further in vivo evaluation.The Indonesian journal of Biotechnology. 06/2012; 17(1):79-89.
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ABSTRACT: Isolation and screening of microorganisms from naturally occurring processes have always been the most powerful means for obtaining useful cultures for scientific and commercial purposes.Lactic acid bacteria commonly used as a natural food preservative, which produces certain antimicrobial substances such as Bacteriocin. The present study deals with isolation and characterization of Bacteriocin producing Lactobacillus sp., from a raw unpasteurized milk sample. Screening and isolation was done on MRS agar, and isolates were identified using biochemical methods. Bacteriocin was produced from promising isolate. Bacteriocin from fermented broth was extracted by solvent extraction and antibacterial activity was determined against selected test microorganisms of both Gram positive and Gram negative groups.This study revealed the possibility of using Bacteriocin as food biopreservative to control food spoilage and pathogenic bacteria.Indian Streams Research Journal, Impact factor 0.2105. 04/2013; 3(3):1 - 7.