Screening of lactic acid bacteria isolated from fermented table olives with probiotic potential

The aim of this work was to study the potential probiotic properties of lactobacilli associated with table olives. From a total of 111 isolates from spontaneously fermented green olive brines, 109 were identified at species level by multiplex PCR amplifications of the recA gene. One hundred and seven of these were identified as Lactobacillus pentosus, one as Lactobacillus plantarum, and another as Lactobacillus paraplantarum. Repetitive bacterial DNA element fingerprinting (rep-PCR) with GTG5 primer revealed a higher variability within the L. pentosus isolates and nine different clusters were obtained. Most of them showed high autoaggregation ability, low hydrophobicity properties, and lower survival to gastric than to pancreatic digestion; however, no isolate showed bacteriocin, haemolytic or bile salt hydrolase activities. A multivariate analysis based on results from phenotypic tests led to the segregation of some L. pentosus isolates with promising potential probiotic characteristics, which are even better than probiotic reference strains. Due to the autochthonous origin of the strains, their use as starter cultures may contribute to improving natural fermentation and the nutritional characteristics of table olives.

► Table olives can be a new interesting probiotic source to consumers. ► Rep-PCR fingerprinting revealed a high variability within the L. pentosus isolates. ► As deduced by PCA, some L. pentosus isolates showed promising probiotic characteristics. ► GG2S-T2-168 and GM2F-T5-327 showed the best potential characteristics. ► Their use as starter culture in table olives could improve safety and sales.