title: Nature of the antimicrobial activity of Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium animalis against foodborne pathogenic and spoilage microorganisms.
abstract: The antimicrobial activities as well as the nature of the inhibitory compounds obtained from Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium animalis strains were assayed on foodborne pathogenic - Staphyloccoccus aureus subsp. aureus (CCUG ATCC® 25926™) and Escherichia coli (ATCC® 25922™) - and spoilage microorganisms - Pseudomonas aeruginosa (ATCC® 27853™). Test producer strains showed inhibitory effect on all indicator microorganisms in diffusion of cell-free concentrated supernatant by agar in well methods (10.0-22.5 mm) in periods of 24, 48 and 72 h. Inhibitory compounds showed no sensitivity to the action of proteolytic enzyme trypsin and were completely inactivated by adjusting the pH of the cell-free 20 × concentrated supernatant to 7.0. The results demonstrated that antimicrobial substances do not have proteinaceous nature and are caused by the action of organic acids with decreasing medium pH.
authors.affiliation: a Laboratory of Genetics of Microorganisms, DBM, CCEN, UFPB , João Pessoa , Brazil.
authors.forename: Cybelle Pereira
authors.initials: CP
authors.lastname: de Oliveira
authors.affiliation: b DTA, CTDR, UFPB , João Pessoa , Brazil.
authors.forename: João Andrade
authors.initials: JA
authors.lastname: da Silva
authors.affiliation: a Laboratory of Genetics of Microorganisms, DBM, CCEN, UFPB , João Pessoa , Brazil.
authors.forename: José Pinto
authors.initials: JP
authors.lastname: de Siqueira-Júnior
mesh_terms: D001644:Bifidobacterium / Q000737:chemistry*; D017077:Culture Media, Conditioned / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D005506:Food Contamination; D005516:Food Microbiology; D007780:Lacticaseibacillus casei / Q000737:chemistry*; D019936:Probiotics; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D017077:Culture Media, Conditioned
keywords: Bifidobacterium; Lactobacillus; antimicrobial compounds; organic acids