Impairment of Listeria monocytogenes biofilm developed on industrial surfaces by Latilactobacillus curvatus CRL1579 bacteriocin

CONSTANZA VICTORIA MELIAN; PLOPER, DIEGO; ROSANA CHEHÍN; GRACIELA VIGNOLO; CASTELLANO, PATRICIA

Food Microbiology

Academic Press

Lugar: Amsterdam; Año: 2024 vol. 121

The effect of lactocin AL705, bacteriocin produced by Latilactobacillus (Lat.) curvatus CRL1579 against Listeria biofilms on stainless steel (SS) and polytetrafluoroethylene (PTFE) coupons at 10 ◦C was investigated. L. monocytogenes FBUNT showed the greatest adhesion on both surfaces associated to the hydrophobicity of cell surface. Partially purified bacteriocin (800 UA/mL) effectively inhibited L. monocytogenes preformed biofilm through displacement strategy, reducing the pathogen by 5.54 ± 0.26 and 4.74 ± 0.05 log cycles at 3 and 6 days, respectively. The bacteriocin-producer decreased the pathogen biofilm by ~2.84 log cycles. Control and Bac􀀀 treated samples reached cell counts of 7.05 ± 0.18 and 6.79 ± 0.06 log CFU/cm2 after 6 days of incubation. Confocal scanning laser microscopy (CLSM) allowed visualizing the inhibitory effect of lactocin AL705 on L. monocytogenes preformed biofilms under static and hydrodynamic flow conditions. A greater effect of the bacteriocin was found at 3 days independently of the surface matrix and pathogen growth conditions at 10 ◦C. As a more realistic approach, biofilm displacement strategy under continuous flow conditions showed a significant loss of biomass, mean thickness and substratum coverage of pathogen biofilm. These findings highlight the antibiofilm capacity of actocin AL705 and their potential application in food industries.