An insight into the microbiota of exotic fruits and flowers of Northern Argentina: molecular identification of lactic acid bacteria

RUIZ RODRIGUEZ, L.; BLECKWEDEL, J.; ILLEGHEMS, K.; WECKX. S.; DE VUYST, L.; HEBERT, E.M.; MOZZI, F.

Simposio; 11th International Symposium on Lactic Acid Bacteria. HEALTH, SUSTAINABILITY, DIVERSITY, AND APPLICATION; 2014

Lactic acid bacteria (LAB) are naturally present in a wide variety of niches. Because of their beneficial properties, LAB are used as starter cultures, as probiotics, and in the production of interesting compounds. Exploring the LAB biodiversity of virgin niches may lead to the isolation of unique strains or species with interesting technological and/or health-promoting properties. A great diversity of exotic fruit trees exist in the Northern region of Argentina, constituting an interesting source of LAB. The present study aimed to isolate and identify LAB from fresh fruits and flowers from Northern Argentina. Guava (yellow and pink varieties), papaya and passion fruits as well as passion fruit flowers were aseptically collected. LAB isolation was performed by culture-dependent techniques, using MRS medium for LAB and FYP medium for fructophilic LAB. One hundred and ninety Gram-positive, catalase-negative isolates were obtained; identification was assayed by RAPD-PCR fingerprinting (M13b and XD9 primers) or rep-PCR fingerprinting analysis [(GTG)5 primer] and numerical clustering. Molecular identification of representative isolates of each cluster was performed by partial sequencing of 16S rDNA. Among the fruit isolates, Enterococcus hirae (1 strain), Ent. casseliflavus (4), Ent. faecium (1), Weissella minor (9), Lactococcus lactis subsp. cremoris (1), Leuconostoc mesenteroides subsp. mesenteroides (3), Leuc. pseudomesenteroides (16), Lactobacillus brevis (6), Lb. plantarum (1) were identified, whereas Ent. faecalis (1), W. cibaria (2), Lc. lactis subsp. lactis (1) and Leuc. mesenteroides subsp. mesenteroides (2) were found in flowers. The results suggest that various LAB species naturally inhabit many exotic fruits and flowers, among which the most abundant strains belonged to the Leuconostoc and Weissella genera. Further studies are needed to evaluate the potential health-promoting or industrially-relevant properties of the strains.A016