A study of heavy metal tolerance of some bacteria and their efficiency in the removal of heavy metals from simulated contaminated soils.
| dc.contributor.author | Feruke-Bello, Yetunde Mutiat | |
| dc.date.accessioned | 2023-05-13T16:59:36Z | |
| dc.date.available | 2023-05-13T16:59:36Z | |
| dc.date.issued | 2015 | |
| dc.description | xxii,210p | en_US |
| dc.description.abstract | Isolation and characterization of some heavy metal resistant bacteria (HMRB) and their efficiency in remediating heavy metals from simulated contaminated soil were carried out. The maximum tolerable concentrations of the isolated bacteria to heavy metals as well as the sensitivities of the bacteria isolates to antibiotics were also determined. This was with a view to developing strains that would have biotechnological applications in bioremediation of the environment. The soil, water and discharged effluent samples were obtained from three selected sites namely; Aruwa village mining sites at Itagunmodi, Waste dumpsite and Biological Sciences Building of Obafemi Awolowo University, Ile-Ife. The samples were analysed using standard laboratory procedures in order to isolate and characterize the heavy metal resistant bacteria. The four (4) most heavy metal resistant bacteria were subjected to chemical mutagenesis and evaluated for their Maximum Tolerable Concentration (MTC) of lead, arsenic, cadmium and nickel; and antibiotic sensitivity profile. The best HMRB wild and mutant strains were evaluated for the heavy metal remediation efficiency under varying pH and metal concentration in the culture supernatant. In addition, the remediation efficiency of the bacteria isolates and its mutant strains were evaluated in simulated contaminated soil using standard laboratory procedures. The total viable bacterial count range were 6.20 × 104 to 6.10 × 107 cfu/g in the soil of Aruwa village, 5.91 × 107 to 6.40 × 104 cfu/ml in the soil of the waste dumpsite, and 5.25 × 107 to 2.0 × 102 cfu/ml in the discharged effluent of Biological buildings, O.A.U. respectively. The MTC for the bacterial isolates in the presence of cadmium, arsenic and lead were: 1200, 4500 and 2000 mg/L for Pseudomonas, Klebsiella and Enterobacter species respectively. The MTC of nickel for Pseudomonas sp. was 600 mg/L while Klebsiella and Enterobacter sp. had an MTC of 1000 mg/L. The identities of the best two HMRB were confirmed to be Pseudomonas aeruginosa and Klebsiella variicola. The MTC determined for P. aeruginosa and K. variicola and their mutants showed that some of the mutants had an increment of between 6 – 32% in MTC to the heavy metals as compared with their wild type. The P. aeruginosa and its wild type were resistant to all the antibiotics tested except for P. aeruginosa MutAc which was sensitive to gentamicin, ofloxacin, ciprofloxacin and nitrofurantoin. However, K. variicola and its wild type were resistant to ceftazidime, cefuroxime, cefixime and augmentin but sensitive or intermediate to gentamicin, ciprofloxacin and nitrofurantoin. A 99.4% and 97.7% removal of 500 mg/L of cadmium in solution by K. variicola MutAc and K. variicola MutEb at pH 7 and 8 respectively were observed, while 99.9% of 500 mg/L of lead was removed by the same mutants. However, in the simulated soil, 15.6% and 14.6% of cadmium, 27.8% and 9.8% of lead was removed from the soil by K. variicola MutAc and K. variicola MutEb respectively. The RAPD-PCR analysis showed genetic relatedness and variation between the K. variicola Wt and its various mutants. The study concluded that K. variicola mutants was effective in the removal of lead and cadmium from simulated contaminated soil and in solutions, hence could be used to clean up heavy metal contaminated environments. | en_US |
| dc.identifier.citation | Feruke-Bello,Y.M.(2015). A study of heavy metal tolerance of some bacteria and their efficiency in the removal of heavy metals from simulated contaminated soils. Obafemi Awolowo University | en_US |
| dc.identifier.uri | https://ir.oauife.edu.ng/123456789/5432 | |
| dc.language.iso | en | en_US |
| dc.publisher | Microbiology,Obafemi Awolowo University | en_US |
| dc.subject | Isolation | en_US |
| dc.subject | Heavy metal | en_US |
| dc.subject | Resistant bacterial | en_US |
| dc.subject | Biotechnological | en_US |
| dc.subject | Antibiotics | en_US |
| dc.title | A study of heavy metal tolerance of some bacteria and their efficiency in the removal of heavy metals from simulated contaminated soils. | en_US |
| dc.type | Thesis | en_US |