Parastrephia quadrangularis : A Possible Alternative to Inhibit the Microbial Effect on the Generation of Acid Mine Drainage

The role of iron- and sulfur- oxidizing microorganisms in the generation of acid mine drainage (AMD) from sulfide ores and tailings is widely recognized. The inhibition of these microorganisms is a very important alternative to mitigate AMD formation and its effects on the environment and ecosystems. Parastrephia quadrangularis (commonly known as Tola–Tola) is a xerophytic plant that usually grows very close to or even on mineral processing tailings located in the Puna region of Argentina. We demonstrate that the aqueous extract of P. quadrangularis is capable of inhibiting the growth of Acidithiobacillus ferrooxidans in suspension. The presence of chlorogenic acid, quinic acid, butyl-1caffeoylquinic, ferulic acid, and euparin, which have already demonstrated antimicrobial action, was detected. The inhibition of A. ferrooxidans could be the basis of a possible alternative to inhibit microbial activity in tailings and thus prevent AMD.