Keywords : MIC

Bioremediation of lead and cadmium and the strive role of Pediococcus pentosaceus probiotic

Raghad Jaafar

Iraqi Journal of Veterinary Sciences, 2020, Volume 34, Issue 1, Pages 51-57
DOI: 10.33899/ijvs.2019.125581.1092

Consumption of food and water contaminated with heavy metals poses a huge threat to the life. Both of Lead (Pb) and Cadmium (Cd) are heavy metals and important environmental pollutants. Away from traditional treatments, the current study aims to adopt probiotic bacteria Pediococcus pentosaceu to treat heavy metal pollution. Present results indicated a good probiotic property of P. pentosaceus, where they were able to survive pH range from 3-9, during incubation periods 3 and 24 hours, and bile salt range 0.15-0.5% for the same period. The number of bacteria in gastric (pH 3) and intestinal juices (pH 8) after 24 hours of incubation was 390 and 205, respectively. Bacteria showed an inhibitory effect against pathogenic bacteria Salmonella sp. The antibiotic susceptibility test revealed them resistant to clindamycin, intermediate resistant against benzylpenicillin, ampicillin, and their sensitivity to the rest tested antibiotics. Isolated bacteria identified based on their morphology, biochemical characteristic in addition to the use of automated instrument for bacterial identification (Vitek II), and depending on the results bacteria were identified as P. pentosaceus. In bioremediation study, the lowest inhibitory concentration of lead and cadmium and (MIC) was done, followed by assay the removal capacity by P. pentosaceus, using atomic absorption spectrometry (AAS) analysis. Bacteria show high MIC (1800 and 150 ppm) for Pb and Cd respectively. With removal efficiency for Pb 62.10-68.39% in the concentrations 25 and 50 ppm, respectively, and for Cd 52.71-11.25% in the same concentrations. Depending on the present finding probiotic bacteria (P. pentosaceus) can apply in the bioremediation of heavy metals in the fish ponds when contamination occurs, in addition to their tradition used as safety additive to prevent fish disease and an enhancement agent .Finally the isolation of these bacteria from fish ponds can be considered as a good indicator for a healthy state of fish ponds in the studied area.