Characterization of lactobacilli from meat and fermented sausages for their potential application as probiotics

PÉREZ IBARRECHE, MARIANA; DE SOUSA, LUCAS; CASTELLANO, PATRICIA; NIÑO ARIAS, FABIÁN CAMILO; DE MARTINIS, ELAINE CRISTINA; LONGO BORGES, LILIANA; SOUZA, VANESSA MACIEL

Medellin

Congreso; XIII Congreso Latinoamericano de Microbiología e Higiene de Alimentos; 2016

Background: Research of new probiotics has received increasing attention as scientific evidence continues to accumulate on their functionality and beneficial effects on humans. Lactobacillus sp. isolated from meat products with anti-listerial activity due to production of bacteriocins may be useful for food biopreservation and for application in probiotic products. Objective: To study selected lactobacilli for acid and bile tolerance, binding to intestinal cells and, antimicrobial activity. Methods: Lactobacillus curvatus CRL705, 1532, 1533 and 1613 were exposed to acid and bile salts, to evaluate their survival under gastrointestinal conditions (with or without the prebiotics inulin and oligofructose). To estimate in vitro the potential of binding to intestine, eukaryotic cell culture (Caco-2) was inoculated with 106 CFU/well, for each lactobacilli strain. The production of bacteriocins by the strains was quantified by the critical dilution method, using Listeria monocytogenes as indicator. Results: L. curvatus CRL705, 1532, 1533 and 1613 (initial load of 108 CFU/ml) did not survive under acid conditions but, in the presence of prebiotics, L. curvatus CRL 1613 and 1533 survived at 102 CFU/ml after 6 hours. Moreover, all strains hydrolyzed bile salts, which lowers with the detergent power of bile and favors the bacterial survival. Bacteriocins produced by L. curvatus CRL705, 1532, 1533 and 1613 in MRS broth, presented respectively activities of 3,200; 1,600; 800 and 800 AU/ml. All Lactobacillus strains adhered to Caco-2 cells, showing an average adhesion of 66%. Conclusion: L. curvatus CRL705, 1532, 1533 and 1613 presented low survival in acid conditions but, bound to epithelial cells (Caco-2), presented anti-listerial activity and deconjugated bile salts. This encourages new studies to improve the survival of these strains under acid condition, likely using the technique of microencapsulation. Financial support: FAPESP 2013/50498-5; CONICET.