Atividade antimicrobiana de Lactobacillus e Bifodobacterium frente a microrganismos patogênicos “in vitro”

Abstract

ResumoLactobacilos e bifidobactérias apresentam um longo histórico de uso seguro em alimentos, além de apresentarem características de interesse biotecnológico como a inibição de patógenos. Neste trabalho duas linhagens de lactobacilos e uma de bifidobactéria, isoladas do intestino humano, foram avaliadas em testes de difusão em ágar, quanto à capacidade de inibição de microrganismos patogênicos de ocorrência comuns em toxinfecções alimentares. Adicionalmente, foram avaliados os metabólitos produzidos em caldo de cultivo estático e em agitação para simular condições de anaerobiose a aerobiose, respectivamente. AbstractLactobacilli and bifidobacteria have a long history of safe use in foods. These bacteria have biotechnological characteristics of interest such as the inhibition of pathogens. In this work, two lactobacilli strain and a bifidobacterium strain isolated from human gut were evaluated concerning to their ability to inhibit pathogenic microorganisms in foods by diffusion agar tests. Moreover, we assessed the metabolites produced in culture broth under static and shaking growth to simulate anaerobiosis and aerobiosis conditions, respectively. L. acidophilus LA5, L. plantarum DCTA 8420 and B. lactis DCTA 8724 showed ability to inhibit S. aureus FRI 196, strains producer toxins A and D, as well as B. cereus ATCC 25923, E. coli ATCC 25922 and S. Enteritidis, whose inhibition halos reached, on average, 24 mm in diameter. In the agar diffusion method with concentrated culture medium, it was possible to observe the effect of oxygen on the production of toxic substances. This result showed that cultivation of Lactobacillus under aerobic conditions seems to exert greater inhibitory effect, whereas for Bifidobacterium strain the effect was the opposite.

Survival of Lactobacillus rhamnosus EM1107 in simulated gastrointestinal conditions and its inhibitory effect against pathogenic bacteria in semi-hard goat cheese

“…stand out among the prevalent pathogenic bacteria that are the etiologic agents of food outbreaks involving dairy products (Cokal, Dagdelen, Cenet, & Gunsen, 2012). Therefore, the addition of probiotic lactic cultures with recognized antimicrobial activity to cheeses can contribute to the maintenance of the microbiological quality of these products during storage (Costa, Suguimoto, Miglioranza, & Gomez, 2012).…”

“…Overall, probiotic strains that exhibit antimicrobial activity against spoilage or pathogenic bacteria within the matrix in which they are incorporated are of interest for industrial application, because in addition to performing their probiotic effect, may contribute to an increase in product shelf life (Costa et al, 2012).…”

Development of stuffed coalho cheese in the traditional, lactose-free and probiotic-added formulations

“…The P cheese samples exhibited a lower count of mold and yeast when compared to T and LF samples (Table 2) which can be explained by the antimicrobial activity that probiotic bacteria displays within the bulk in which they are incorporated (MARIANELLI;CIFANI;PASQUALI, 2010;COSTA et al, 2012;PENG et al, 2015).…”

Ação antagonista de lactobacillus acidophilus frente a estirpes patogênicas inoculadas em leite fermentado

“…Analisando a Figura 1, observa-se que E. coli (I1) não foi mais detectável no produto a partir do vigésimo quinto dia de estocagem, quando ocorreu morte celular, provavelmente por exclusão competitiva por nutrientes ou pela ação de ácidos orgânicos como descrito por Calderon et al 35 , Alves 36 , Costa et al 37 e Marques et al 38 .…”