Isolation, Identification and Characterization of Some Bacteria from Soil Samples of Agbaja Iron Ore Mining Site of Kogi State

Abstract

Hydrometallurgical and other conventional mining technologies on low grade ores require high energy and capital costs. The use of microbes to degrade such type of minerals is gaining acceptance. This study was carried out, therefore to isolate, identify and characterize iron solubilizing bacteria from Iron stones of Agbaja iron ore mining site of Kogi State. Crushed samples in the range of 0.25µm and 0.75µm particle size were used for the isolation. They were cultured in a modified 9k media to facilitate bacterial growth and pure cultures were then isolated and sub-cultured for further identification. Morphological and biochemical analysis suggests that some of the bacteria identified are members of Acidithiobacillus, Pseudomonas, and Leptospirillum species. Also results of growth pattern due to bacteria count obtained after 24hours, 48hours and 72hours of incubation ranged between 0.1×10 3 cfu/ml and 12.3 ×10 3 cfu/ml. The highest count of 12.3 ×10 3 cfu/ ml was obtained in Pit 4 at 72hours. At 24hours there was no visible count in Pit 5 and 4, while at 48hours pit 4 was 1×10 3 and pit 5 was 2.6×10 3 and finally at 72hours pit 4 and 5 was 12.3×10 3 and 4.3×10 3 respectively, incubation time, and temperature, further confirms that these isolated species are mesophilicacidophiles with good bioleaching properties.

Physicochemical and molecular characterization of heavy metal–tolerant bacteria isolated from soil of mining sites in Nigeria

“…In contrast to the findings obtained in this study, Margesin et al [ 41 ] reported larger counts of cultivable bacterial communities in heavily contaminated soil polluted by heavy metals. Other studies by Emmanuel et al [ 42 ] reported a lower bacterial count (12.3 × 10 3 cfu/g) in the soil of mining sites in Nigeria.…”

“…The heavy metal–tolerant isolates recovered were Gram negative, which studies [ 42 , 43 ] showed to be more tolerant to heavy metals than Gram positive. This attribute could be due to the interaction between the bacterial cell wall and the metal ions on the surface and the interface of the bacteria.…”

Physiochemical analyses and molecular characterization of heavy metal-resistant bacteria from Ilesha gold mining sites in Nigeria

“…Ten heavy metal-tolerant isolates were recovered of which preliminary identification analysis revealed five to be Gram-positive while the other five were Gram-negative. Interestingly, studies have shown that Gram-negative bacteria are more tolerant to heavy metals than Gram-positive bacteria, a phenomenon which has been suspected to be due to the ability of their cell wall to interact with the metal ions on the surface and the interface of the bacteria [28,46]. Further subjection of the bacteria isolates to minimum inhibitory concentration tests revealed isolates 2, 6, 7, and 9 as the isolates capable of tolerating high concentrations of Pb, Co, Cd, Zn, and Hg as evident in Table 9.…”

“…The morphological characteristics of the bacteria colonies such as edges, shape, and surface were observed and recorded [28]. The identification and characterization of bacteria isolates were performed by carrying out grams staining and other relevant biochemical tests which include catalase test, coagulase test, indole production test, citrate utilization test, and sugar fermentation [29,30].…”