Lactic acid bacteria are proposed as an innovative eco-friendly strategy to control relevant food-borne pathogens including Listeria monocytogenes and L. monocytogenes represent a safety concern for the food industry due to its ability to survive and grow under several harsh conditions associated with food processing and preservation. In addition, L. monocytogenes may persist in food plants and equipment since able to form biofilms. In the present work, we screened 152 lactic acid bacteria for their ability to inhibit the growth of L. monocytogenes serovar ½a and 4b from animal and vegetable origin. The antagonistic effect was investigated by analysing the halo of inhibition on agar plates co-inoculated with LAB strains or in presence of the correspondent cell-free supernatant. The same approach was employed to evaluate the reduction of biofilm formation on glass, polystirene, and stainless steel. L. monocytogenes biofilms were quantified spectrophotometrically and the viability of the pathogen assessed by qPCR. LAB were clustered in four categories according to their inhibitor effect. The strains with the stronger antagonistic activity suggest a potential employment to control L. monocytogenes proliferation and the corresponding biofilm formation in food processing and plants.
Antimicrobial activity of lactic acid bacteria on biofilm formed by Listeria monocytogenes
SPANO, GIUSEPPE;ARENA, MATTIA PIA;CAPOZZI, VITTORIO;RUSSO, PASQUALE
2014-01-01
Abstract
Lactic acid bacteria are proposed as an innovative eco-friendly strategy to control relevant food-borne pathogens including Listeria monocytogenes and L. monocytogenes represent a safety concern for the food industry due to its ability to survive and grow under several harsh conditions associated with food processing and preservation. In addition, L. monocytogenes may persist in food plants and equipment since able to form biofilms. In the present work, we screened 152 lactic acid bacteria for their ability to inhibit the growth of L. monocytogenes serovar ½a and 4b from animal and vegetable origin. The antagonistic effect was investigated by analysing the halo of inhibition on agar plates co-inoculated with LAB strains or in presence of the correspondent cell-free supernatant. The same approach was employed to evaluate the reduction of biofilm formation on glass, polystirene, and stainless steel. L. monocytogenes biofilms were quantified spectrophotometrically and the viability of the pathogen assessed by qPCR. LAB were clustered in four categories according to their inhibitor effect. The strains with the stronger antagonistic activity suggest a potential employment to control L. monocytogenes proliferation and the corresponding biofilm formation in food processing and plants.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
