European Journal of Biomedical and Pharmaceutical Sciences

POTENTIAL ASSESSMENT OF BACILLUS COAGULANS FOR BIOREMEDIATION OF ZN (II) AND NI (II): AN IN VITRO STUDY

Pranoti Belapurkar*, Pragya Goyal and Anand Kar

ABSTRACT

To understand the microbe-metal relationship in terms of the bioremediation strategies in nature, a study was undertaken to assess the potential of Bacillus coagulans, a probiotic species of genus Bacillus, for bioremediation of Zn (II) and Ni (II) in vitro. The minimum inhibitory concentration of B. coagulans against Zn (II) was found to be 16 ppm while it was 256 ppm for Ni (II), indicating that the test organism can tolerate Ni (II) better than Zn (II). When Zn (II) and Ni (II) tolerant culture was grown on nutrient agar medium, no variation was observed in its colony morphology, staining and biochemical properties as compared to the unexposed culture. Both exposed and unexposed cultures of B. coagulans were tested for their antibiotic sensitivity against seven antibiotics. The Zn (II) tolerant culture showed increased sensitivity against most of the antibiotics especially against ciprofloxacin, teicoplanin and norfloxacin. However, no change in sensitivity was obtained against kanamycin. Ni (II) tolerant culture showed significant increase in sensitivity against almost all antibiotics tested against it. When Zn (II) tolerant culture was tested for any change in its probiotic efficacy, it showed highest bile tolerance at 0.3% bile (w/v) after 3 hrs and showed acid tolerance at pH 3. Similar results were obtained for Ni (II) tolerant culture. These results indicate that even under heavy metal stress B. coagulans did not undergo any change and maintained its probiotic nature, thus suggesting its great potential to bioremediate the two test heavy metals, possibly in in vivo condition as well.

Keywords: Bioremediation, Probiotic, Heavy Metals, MIC, Antibiotic Sensitivity.