Evaluation of Heavy Metal Tolerance Level (MIC) and Bioremediation Potentials of Pseudomonas aeruginosa Isolated from Makera-Kakuri Industrial Drain in Kaduna, Nigeria

Abstract

Bacterial strains isolated from the Kakuri drain were characterized and subjected to various concentrations of heavy metal salts and their ability to tolerate the heavy metals (Minimum Inhibitory Concentration-MIC) was determined. This shows their ability to tolerate and survive in environments with high levels of heavy metal salts. Eight(8) heavy metals were considered , and included ; Cobalt Chloride (CoCl2), Cadmium Chloride (CdCl2),Copper Sulphate (CuSo4), Mercury Chloride (HgCl2), Nickel Chloride (NiCl2), Potassium Dichromate (K2Cr207), Lead Chloride (PbCl2) and Zinc Sulphate (ZnS04). Strains were subjected to varied millimolar concentrations (1, 2, 5, 10, 20, 30 and 50 mM). Positive and Negative controls were set up to a certain the tolerance level amongst the strains. 100% growth of all strains was observed at 1 mM concentration, while 100% growth was recorded with CuS04, ZnS04 and HgCl2. Most strains were inhibited or could not tolerate the salts at 10 mM concentration, with the exception of ZnS04, PbCl2, and CdCl2. No growth (100% inhibition) was noticed on plates with 20, 30, 40 or 50 mM concentrations. It therefore shows that the strains isolated from the kakuri drain could withstand presence of heavy metals salts up to a concentration of 10 mM.