Characterization of lactic acid bacteria isolated from wheat bran sourdough

Abstract

Spontaneously fermented foods, such as sourdough, represent a source of lactic acid bacteria with potential interesting functional and technological properties as well as a potential source of probiotics. The choice of the starter cultures has a critical impact on the palatability, processability and nutritional attributes of fermented products. The aim of this study was to characterize the predominant microbial species previously isolated from a sourdough-like spontaneous fermented wheat bran. Lactic acid bacteria, such as Leuconostoc mesenteroides, Leuconostoc citreum, Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus sakei, Lactobacillus plantarum and Pediococcus pentosaceus, were phenotypically characterized by their growth and acidification rate, carbohydrate metabolism, antifungal activity, exopolysaccharide production, as well as safety. The strains were also tested for xylan- and phytate-degrading activities. Moreover, probiotic properties, such as acid and bile tolerance, anti-listeria activity and adhesion ability to Caco-2 cells were examined. L. plantarum CE42, CE60 and P. pentosaceus CE65, CE23 showed interesting technological application potential due to their antifungal activity and exopolysaccharide production. Some strains also exhibited phytate degrading activity and could be exploited to improve mineral bioavailability of fermented products. Moreover, P. pentosaceus CE65 seems to be a candidate for use as probiotic.