Abstract

Four soil samples and water effluents each within the mining environment were tested in this study. Twenty six bacteria were isolated using nutrient agar and acidified nutrient agar. Gram staining and endospore staining were carried out to determine the Bacillus species used for bioremediation. Speciation of the microorganisms using 16S rRNA sequencing showed the organisms to be Bacillus cereus NK1, Lysinibacillus species TAI-282, Lysinibacillus fusifomis, Bacillus aryabhattai PM1 and Bacillus megaterium from the samples. The temperature of the water effluents ranged from 29.00 to 34.70°C. Sample C from beneficiation area had the highest temperature of 34.70°C. The pH ranged from 6.70 to 9.77 with effluent from primary crushing area two (PC2) having the highest of 9.77. Bioremediation of the water samples were carried out for 6 days using the identified Bacillus species from the mine site. For all the effluents treated, there was an increase in the concentration of magnesium with effluent from PC2 treated with L. fusifomis increasing to 7.453±0.004 from 4.278±0.003 and these values were significantly different at p≤0.05. Concentration of calcium in effluent from iron ore storage area increased from 1.350 ±0.002 to 15.450±0.004 after treatment with B. aryabhattai PM1, and the values were significantly at p≤0.05. Bacillus spp. from PC2 reduced the concentration of iron from 179.738 to 0.091 ppm on effluent from PC1, the concentration was significantly different at p≤0.05. The indigenous microorganisms from within the iron ore mining site had bioremediation potentials reducing the concentrations of most of the heavy metals present.

Key words: Iron ore, molecular analysis, bioremediation, Bacillus species.