Screening of Potential Probiotic Properties of Lactobacillus and Lactococcus strains

Abstract

The lactic acid bacteria are known to be probiotic and their important role has been known in making the biotechnological products and improving human health. Effective probiotic should be viable, safe, bile and gastric juices tolerant, able to survive throughout the human gastrointestinal tract and to colonize a specific human tract. We aimed to investigate and compare the probiotic potential of the Lactobacillus helveticus ATCC 15009 (L. helveticus), Lactobacillus plantarum ATCC 14917 (L. plantarum), Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 (L. bulgaricus), Lactococcus lactis IL1403 (L. lactis IL1403) and Lactococcus lactis IL1403 bearing pSIP plasmid (L. lactis IL403 pSIP) in different aspects that include their ability to tolerate acidic conditions, gastric acid and intestinal juice. We also evaluated their hydrophobicity and antibiotic sensitivity. The Lactobacillus and Lactococcus species were grown at 37 °C and 30°C respectively in different pH, simulated gastric acid and intestinal juice. Four of the bacteria displayed good probiotic features in low pH. Even though L. lactis IL1403 did not survive in L. pH 4.0. Among the tested organisms, cell surface hydrophobicity of L. helveticus was recorded as 79.80±0.008 at Xylene as a highest value. We also found that all bacterial strain could attain to the large intestinal area after 25 hours and are sevsitive to rifampin, chloramphenicol, gentamycin, penicillin and neomycin. Our results suggest that these strains can confer good probiotic but they need to use considering their specific features in accord with therapeutic and biotechnological purposes.