Biotic Acid Mine\nDrainage (AMD) Suppression Using\nBiogas Slurry: Identification of Key Inhibitory Components and Molecular\nInactivation Mechanism of Acidithiobacillus ferrooxidans

Acid mine drainage (AMD) is a significant environmental\nchallenge,\nand its treatment can be expensive and complicated. <i>Acidithiobacillus</i> could accelerate the rate of AMD formation by 5–6 orders\nof magnitude. Acidithiobacillus ferrooxidans (A. ferrooxidans) is the model species\nof <i>Acidithiobacillus</i>. We initially tried to use the\nbiogas slurry as an organic additive to prevent AMD formation. We\ndetermined the essential inhibitory components of the biogas slurry\nas organic acids (acetic acid (AA), a typical example). The results\nrevealed that AA (≥50 ppm) prevented A. ferrooxidans from forming AMD. The transcriptomic and untargeted metabolomic\nevaluation found 324 differentially expressed genes and 35 significantly\ntransformed metabolites. Combinatorial omics analysis showed that\nthe presence of AA significantly inhibited the membrane biogenesis,\nFe<sup>2+</sup>, and RISC metabolism pathways, reducing energy metabolites\nsuch as Fe<sup>3+</sup> and SO<sub>4</sub><sup>2–</sup>. Furthermore,\nAA treatment induced A. ferrooxidans defense mechanisms and overconsumed its internal carbon sources.\nThese findings proved that biogas slurry had a significant inhibitory\neffect on key microorganisms in highly acidified mineral soils and\nprovided a scientific foundation for the prevention of acidification\nand the ecological restoration of newly mined areas.