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Bacteriocin production and inhibition of Listeria monocytogenes by Lactobacillus sakei subsp. sakei 2a in a potentially synbiotic cheese spread

Martinez, Rafael Chacon Ruiz, Staliano, Cristina Dini, Vieira, Antonio Diogo Silva, Villarreal, Martha Lissete Morales, Todorov, Svetoslav Dimitrov, Saad, Susana Marta Isay, Franco, Bernadette Dora Gombossy de Melo
Food microbiology 2015 v.48 pp. 143-152
Lactobacillus sakei, Listeria monocytogenes, antibacterial properties, bacteriocins, cheese spreads, gene expression, inulin, lactic acid bacteria, phenotype, plate count, prebiotics, quantitative polymerase chain reaction, reverse transcriptase polymerase chain reaction, serotypes, temperature
Survival, bacteriocin(s) production, and antilisterial effect of Lactobacillus sakei subsp. sakei 2a were evaluated in a potentially synbiotic cheese spread, throughout storage at 4 °C and 15 °C for up to 28 days, using culture-dependent (plate count) and culture-independent (qPCR) methods. Bacteriocin(s) production in the food product was monitored by phenotypic and molecular (RT-qPCR) techniques. Three cheese spread trials (T) containing the prebiotic fiber inulin were produced in duplicates and studied: T1 (control – without inoculation of lactic acid bacteria); T2 (inoculated with the non-bacteriocinogenic Lb. sakei ATCC 15521 strain), and T3 (inoculated with the bacteriocinogenic Lb. sakei 2a strain). The cheese spreads were challenged with Listeria monocytogenes serotypes 4b and 1/2a, individually added to the food product. The counts of Lb. sakei 2a in the cheese spread T3 remained high during storage and the growth of L. monocytogenes was inhibited at both temperatures, especially L. monocytogenes 4b in the food product kept at 15 °C due to the production of bacteriocins (up to 6,400 AU/mL). Expression of the genes sakP and sakQ encoding for bacteriocins production during the cheese spread storage was demonstrated. Lb. sakei 2a can be used for production of potentially synbiotic cheese spreads with increased safety.