| Abstrakt: |
The aim of the work was to evaluate antagonistic activity of Lactobacillusspp. and Bifidobacteriumspp. in vitro against cariogenic Streptococcus mutansUA 159 and viability in chewing gum, during storage. Antagonistic activity was evaluated in vitro by the “spot on the lawn” test. Two bacteria were chosen and subjected to lyophilization and microencapsulation using the atomization method, containing polyvinylpyrrolidone polymer and lactose as encapsulating agents. For application in food matrices, four treatments were elaborated: chewing gum containing lyophilized B. lactisB94 (BLL), microencapsulated B. lactisB94 (BLE), lyophilized L. brevis(LBL), and microencapsulated L. brevis(LBE). Both microorganisms demonstrated a high capacity for inhibition against S. mutans, when compared to oral antiseptic chlorhexidine 0.2% in vitro, and according to the test of sensitivity profile to proteolytic enzymes, all the bacteria tested are producers of antimicrobial peptides, resulting in the inhibitory activity of the cariogenic bacterium. Furthermore, the viability of B. lactisB94 and L. breviswas maintained after microencapsulation, indicating that the process was efficient, with no significant difference (p< 0.05) between the results. And, in the chewing gum containing the bacteria during the storage period (33 days), it was found that cell immobilization did not significantly influence (p< 0.05) the counts of L. brevisbut benefited the viability of B. lactisB94. Therefore, both probiotic bacteria are producers of antimicrobial substances with the ability to inhibit S. mutans, in vitro. The microencapsulation was considered efficient since it influenced the viability of B. lactisB94 (> 8 log CFU/g); however, the microencapsulation did not influence the viability of L. brevissince in both lyophilized and encapsulated form; the concentration of the bacteria remained above 8 log CFU/g during the storage period of the chewing gum. |
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