Selection of Lactobacillus plantarum strains for their use as starter cultures in Algerian olive fermentations

Abstract

RESUMENSelección de cepas de Lactobacillus plantarum para su uso como cultivos iniciadores en la fermentación de aceitunas de Argelia.El objetivo de esta investigación fue evaluar algunos aspectos tecnológicos de cepas de L. plantarum previamente aisladas de aceitunas fermentadas. Para este propósito, 11 cepas fueron usadas para estudiar su susceptibilidad a antibióticos in vitro, resistencia a valores de pH bajos, actividad acidificante, proteolítica, y hemolítica, producción de ácido láctico y exopolisacáridos, y resistencia a la liofilización. En general, las cepas fueron susceptibles a la mayoría de los antibióticos ensayados y mostraron supervivencia a pH 2. La mayoría de las cepas mostraron una actividad de acidificación alta (1.035 ± 0.29 a 0.912 ± 0.21 mmol/l de áci-do láctico) o media (0.556 ± 0.29 a 0.692 ± 0.18 mmol/l) con una buena actividad proteolítica (1.49 ± 0.25 a 5.25 ± 0.11 mg l -1 tirosina). Ninguna de las cepas produjo exopolisacári-dos o hemolisis en sangre de oveja.PALABRAS CLAVE: Aceitunas fermentadas -Antibióti-cos -Cultivos iniciadores -Lactobacillus plantarum. SUMMARY Selection of Lactobacillus plantarum strains for their use as starter cultures in Algerian olive fermentations.The aim of this research was to evaluate some technological traits of L. plantarum strains previously isolated from fermented olives. For this purpose, 11 strains were tested for their in vitro antibiotic susceptibility, resistance to low pH values, acidifying activity, proteolytic activity, haemolytic activity, lactic acid and exopolysaccharide production and resistance to freeze-drying .Collectively, the strains were susceptible to most of the antibiotics tested and showed survival at pH 2. Most strains showed high (1.035 ± 0.29 to 0.912 ± 0.21 mmol/l ± sd of lactic acid) or medium (0.556 ± 0.29 to 0.692 ± 0.18 mmol/l±sd) acidification activity with good proteolytic activity (1.49 ± 0.25 to 5.25 ± 0.11 mg l -1 tyrosine). None of the strains produced exopolysaccharides or haemolysis in sheep's blood.

Table Olives More than a Fermented Food

“…Thus, several studies have been conducted to assess the probiotic effects of strains isolated from different fermented olives cultivars and/or already used as starter cultures, belonging to the most widely spread species L. plantarum and L. pentosus, as well as to species less frequently used, such as L. paracasei, L. casei, and L. paraplantarum [43,85,[100][101][102][103][104][105][106]. Some studies revealed that some LAB strains isolated from table olives were able to adhere to porcine jejune epithelial cells IPEC-J2 and produced antimicrobial compounds able to inhibit Helicobacter pylori, Propionibacterium spp., and Clostridium perfringens [10,70,[107][108][109]. Probiotic potential, based on the ability to outcompete foodborne pathogens for cell adhesion, was also characterized in several L. pentosus isolated from different table olive cultivars (i.e., Nocellara del Belice and Aloreña green table olives) [103,110].…”