Dynamic changes in structure and function of a synthetic microbial community during the bioleaching of pyrite and chalcopyrite

Abstract:

Background Bioleaching of sulfide ores by acidophilic microorganisms is an effective approach for metal extraction. However, the activity of natural microbial communities is often unstable due to environmental influences.Objective This study constructed a synthetic microbial community comprising six acidophilic (mesophilic or thermophilic) bacterial strains (Acidiphilium cryptum S30H60, Acidithiobacillus caldus SM-1, Acidithiobacillus ferrooxidans KD-1, Alicyclobacillus ferrooxydans TC-34, Leptospirillum ferriphilum T30-1, and Sulfobacillus thermosulfidooxidans T09-1) and one acidophilic thermophilic archaeon (Ferroplasma thermophilum Ferro). The study aimed to investigate the dynamic changes in community structure and function during the bioleaching of pyrite and chalcopyrite at different temperatures.Methods Community dynamics were monitored by qPCR, and the physicochemical parameters of the leaching solution and mineral surface morphology were analyzed. The data were analyzed to reveal the succession patterns of the microbial community and its impact on leaching efficiency under varying temperatures and mineral types.Results The leaching efficiency at 42 ℃ was significantly higher than that at 30 ℃. The microbial community was dominated by S. thermosulfidooxidans and L. ferriphilum. Certain microbial species exhibited distinct preferences for leaching different sulfide minerals.Conclusion Temperature and mineral type significantly influenced the structure and function of the synthetic microbial community. The synergistic dominance of thermophiles at high temperatures enhanced the leaching efficiency. These findings provide a basis for targeted optimization of bioleaching processes.