Growth in Ever-Increasing Acidity Condition Enhanced the Adaption and Bioleaching of Leptospirlium Ferriphilum

Abstract

Low pH could eliminate the jarosite accumulation and improve the interfacial reaction rate during bioleaching process. However, a great challenge existed between microbial activity and bioleaching ability in low pH conditions. This study demonstrated that the adaption and bioleaching of Leptospirilum ferriphilum could be improved after long term adaptive evolution under acidity condition. It was found that the acidity adapted strain showed robust activity in wider pH, high concentration of ferrous iron and lower temperature. Although the enhancement for heavy metal tolerance was limited, the tolerance for MgSO4, Na2SO4 and organic matter was great. More importantly, both pyrite and printed circuit boards bioleaching revealed the higher bioleaching ability of the acid-resistant strain. These adaptation and bioleaching details provided an available approach for the improvement of bioleaching techniques.