Abstract: The present study was designed to screen 16 strains of lactic acid bacteria isolated from Zuolajiao for their probiotic potential for the development of functional foods. The acid production rates and resistance to artificial gastric juice of these isolates were comparatively evaluated. They were identified by biochemical tests and 16S rDNA sequence analysis. In addition, their probiotic properties were evaluated with respect to stress tolerance, surface hydrophobicity, auto-aggregation ability, antibacterial activity, antioxidant capacity, nitrite degradation ability and safety. Three potential probiotic strains, namely Lactobacillus fermentum 17-1 and 18-2 and Lactobacillus brevis L3-5 were found to be tolerant to 0.4% phenol, lysozyme and heat treatment and have high surface hydrophobicity and auto-aggregation ability. They could produce broad-spectrum bacteriocins against pathogenic bacteria. L3-5 and 17-1 had stronger antioxidant potential. All strains exhibited bile salt hydrolase activity and γ-aminobutyric acid producing ability and were safe. In conclusion, Zhalajiao is a new natural source of probiotics, and L. fermentum 17-1 and 18-2 and L. brevis L3-5 can be used as potential probiotic strains.

Key words: Zuolajiao, probiotic, isolation, functional properties, antioxidant activity