INVESTIGADORES
VIGNOLO Graciela Margarita
congresos y reuniones científicas
Título:
Biofilm formation by meat-borne anti-listerial Lactobacillus strains on industrial surfaces at low temperature.
Autor/es:
PEREZ IBARRECHE, MARIANA; PEÑA, NATALIA; CASTELLANO, PATRICIA; VIGNOLO, GRACIELA
Lugar:
Istambul
Reunión:
Simposio; FoodMicro 2012. 23rd. International ICFMH Symposium.; 2012
Institución organizadora:
ICFMH
Resumen:
Research on microbial biofilms has been documented in many areas with particular emphasis on the evaluation of various control strategies for either preventing or remediating pathogenic biofilm colonization. Listeria monocytogenes is well known for its ability to form biofilm and to establish harborages on food-processing equipment making its eradication even more difficult, which may lead to food products contamination. Many lactic acid bacteria (LAB) are known for their ability to inhibit growth of spoilage and pathogenic microorganisms by producing antimicrobial compounds. In addition, some studies have reported the capacity of three Lactobacillus strains to grow on different surfaces as biofilm without losing their ability to produce inhibitory metabolites such as bacteriocins. In this work the ability to inhibit pathogen biofilm formation by bacteriocinogenic and biofilm producer lactobacilli during 10 days at low temperature was investigated. Petri dish containing MRS broth and stainless steel (SS) and polytetrafluoroethylene (PTFE) chips (1 cm2) of were inoculated with each biofilm- and anti-Listeria compound-producing Lactobacillus strains; the chips were incubated at 10 °C during 4, 6 and 10 days and then evaluated by scanning electron microscopy (SEM). The micrographs showed that all three strains were able to colonize PTFE surfaces as biofilm while no lactobacilli cells were found on SS chips after 4 days. Three-dimensional structures appeared as aggregates that evolved to dense bacterial mats, in which spaces or channels could be distinguished with high magnification. After 6 days, a slower colonization of Lactobacillus sakei CRL1862 on both surfaces was observed while L. curvatus CRL705 and CRL1532 showed similar dense bacterial mass. At day 10, L. curvatus CRL1532 population remained stable whereas few and any cells of L. sakei CRL1862 and L. curvatus CRL705, respectively, were observed on PTFE surface. Interestingly, some microscopic views revealed the presence of fibrils around Lactobacillus cells attached to PTFE chips, which are likely to be polymeric material such as exopolysaccharides. Few and single lactobacilli cells were attached to the SS chips, and no obvious attachment matrix was apparent at days 6 and 10. In line with these findings, the three evaluated Lactobacillus strains have the potential to form biofilms more efficiently in PTFE than SS surface at a low temperature of 10 ºC.