Introduction:

From a microbiological point of view, Staphylococcus aureus is one of the main contaminants causing foodborne illnesses, with symptoms such as nausea, vomiting, diarrhea, abdominal cramps, joint or back pain and fatigue. Bacterial resistance of pathogenic bacteria has recently been found to be a public health problem. An alternative is the use of microencapsulated probiotics for the inhibition of pathogenic microorganisms such as Lactobacillus casei.

Objective:

Evaluate microencapsulated Lactobacillus casei ATCC 393® under in-vitro conditions simulating the gastrointestinal environment and the inhibitory potential on Staphylococcus aureus ATCC BAA 1708®.

Materials and methods:

Reconstitution, seeding and adjustment of the inoculum; antibiogram of the two bacterial strains; fermentation kinetics of Lactobacillus casei; identification of peptides, amino acids and lactic acid of the supernatant; resistance of Lactobacillus casei to different temperatures (37 °C and 45 °C); microencapsulation of Lactobacillus casei; study, characterization and exposure to simulated gastrointestinal conditions of the microencapsulate after 90 days of storage and production of Exopolysaccharides.

Results:

The results indicate inhibitory action of the Lactobacillus casei strain against pathogenic bacteria; exponential phase at 15 hours (MRS culture medium) and 18 hours (PRO culture medium); results of the microencapsulation study and analysis: viability 100 %; efficiency 84,64 %; humidity 4,0 %; solubility 99,8 %; wettability 2 min with 22 seconds; water activity 0,617 and particle size between 2,10 μm and 5,28 μm.

Conclusion:

It was concluded that the microencapsulated Lactobacillus casei showed inhibitory properties against the pathogenic strain.

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