In Vitro Screening For Probiotic Potential Of Lactobacillus Strains Isolated From Algerian Fermented Products

The objective of this study was to isolate and select Lactobacillus strains with probiotic features for a potential use as starter for the preservation of animal feed. Olives, cow's and camel's milk, butter, beer drech and maize silage were used as isolation sources. Molecular identification using 16S rRNA gene sequencing identified four isolates of Lactobacillus plantarum and three of Lactobacillus fermentum. The different screening tests revealed that four strains: Lactobacillus plantarum OV13, Lactobacillus sp. OV15, Lactobacillus fermentum E161 and Lactobacillus sp. E631 are the best probiotic candidates, based on the results of their tolerance to acidic pH between 2 and 3.5, to 0.3% bile, to artificial gastric conditions for 18h of incubation, to their antibiotics resistance, their inhibition power on pathogenic bacteria (Pseudomonas sp., Staphylococcus aureus, Escherichia coli and Listeria ivanovii), and finally to their adhesion capacity to intestinal epithelial cells. The selected probiotic strains are considerate as good candidates for further investigation and should be tested, in vivo, to elucidate their potential health benefits on the animal performance as novel probiotic starters.