CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Identification and functionalities of Lactic Acid Bacteria isolated from fermented potatoes (tocosh)
Autor/es:
VIGNOLO, GRACIELA; JIMÉNEZ, EUGENIA; RAMOS VÁZQUEZ, ELENA; ZÚÑIGA DÁVILA, DORIS; YÉPEZ, ALBA; HEBERT, ELVIRA MARIA; COCCONCELLI, PIER. S.; AZNAR, ROSA
Lugar:
Egmond aan Zee
Reunión:
Simposio; 11th International Symposium on Lactic Acid Bacteria. Health, Sustainability, Diversity, and Application; 2014
Institución organizadora:
FEMS
Resumen:
Tocosh is a traditional fermented potatoes-based food produced in the Central Andean region of Peru, which is produced by placing different potato varieties on a straw bed in a hole practiced near a water spring. Besides being the main staple food for local population, tocosh is claimed to exert probiotic and antibiotic effects. Samples were collected from 0 (fresh potatoes, T1), 1 (T2) and 8 (M3) month-holes for lactic acid bacteria (LAB) isolation and identification. LAB counts were observed to increase (from 104 to 108 CFU/g) whereas pH varied from 5.5 to 4.2 during eight months fermentation period. All 152 presumptive LAB were subjected to identification by ISR-PCR and RAPD-PCR profiles, species specific PCR and 16S rRNA gene sequencing. Results showed that fresh and one-month stored potatoes were dominated by Leuconostoc mesenteroides (76%, 57%, respectively) and Lactobacillus sakei (24%, 43%, respectively) while LAB from 8-months hole potatoes exhibited the highest diversity involving L. sakei (42%), Lactobacillus curvatus (27%), Lactobacillus paracasei (22%) and to a minor extent Lactobacillus casei, Lactobacillus brevis, Lactobacillus fermentum and Leuc. mesenteroides. Functionalities of 43 selected LAB strains were assayed and they showed potential phytate degrading activity (74%), but no amylase; ability to grow in free folate media (70%) and tolerance to 12% alcohol (28%). In addition, most of them (53%) exhibited antifungal activity against Aspergillus oryzae. Extra or intracellular folate producers were Lc. mesenteroides, Lb. sakei and Lb. paracasei. Tocosh enrichment with lactobacilli species during fermentation would support the beneficial effects attributed to this traditional product. Information on unknown microbial genetic resources can be exploited as new functional cultures to improve nutritional and functional quality of other starchy products.