Antibiotic susceptibility and bioremediation potential of probiotic bacteria against lead and cadmium isolated from yogurt.

Probiotic bacteria have capacity to bind with heavy metals. The present study was planned to assess the bioremediation potential of probiotic Lactobacillus species isolated from yogurt samples. L. acidophilus and L. plantarum were tested for acidic pH tolerance, bile salt resistance and gastric juice tolerance. The antibiotic susceptibility and antimicrobial activity was also checked. These Lactobacillus species were also evaluated for degradation of lead (Pb) and cadmium (Cd) metals. The results indicated that L. acidophilus and L. plantarum were able to tolerate high acidic pH: 3. both showed significant growth after exposure to stimulated gastric juice from 0 to 24 hours. The significant plate count was observed at different bile salt concentrations (0.1%, 0.3%). The isolates showed resistance for all the tested antibiotics except L. acidophilus showed susceptibility for gentamicin and co-amoxiclave. The isolates depicted no antimicrobial activity against the indicator bacteria. L. acidophilus and L. plantarum were capable of tolerating Cd and Pb. Maximum tolerance and removal were observed for Pb by both Lactobacillus spp. The Cd removal was 11.50 and 3.50% while Pb removal was 42.70 and 35.50% for L. plantarum and L. acidophilus, respectively. In conclusion, L. acidophilus and L. Plantarum have potential for bioremediation of heavy metals.