Microbial Amelioration of Acid Mine Drainage Impaired Soil using the Bacterial Consortia of Klebsiella sp. and Raoultella sp.

초록

Acid mine drainage (AMD) resulting from pyrite oxidation in mining areas, subsequently leads to soil acidificationaccompanied by lowering pH and high concentration of metals and metalloids in its surrounding environment. Regardingto this, the microbial amelioration has been considered as a promising option for a more cost-effective and eco-friendliercountermeasure, compared to the use of alkaline chemicals. This study was aimed to evaluate influencing factors inmicrobially-mediated amelioration of acidic soil spiked by simulated AMD. For this, microcosm experiments wereconducted by acid-neutralizing bacterial consortium (dominated by Klebsiella sp. and Raoultella sp.) under the variousconditions of AMD spikes (0-2,500 mg SO42/L), together with acidic mine soil (0-100 g) or sphagnum peat (0-5 g) in the200 mL of nutrient medium. The employed bacterial consortium, capable of resisting to high level of sulfate concentration(up to 1,500 mg SO42/L) in low pH, generated the ammonium while concomitantly reduced the sulfate, subsequentlycontributing to the effective soil stabilization with an evolution of soil pH up to neutral. Furthermore, it demonstrates thatsuitable condition has to be tuned for successful microbial metabolism to facilitate with neutralization during practicalapplication.

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