Enhanced pyrite bioleaching through the synergistic interactions between Sulfobacillus thermosulfidooxidans and Alicyclobacillus ferrooxydans

Abstract

With the growing challenges of resource shortages and environmental pollution, bioleaching has attracted increasing attention for its high potential in processing refractory and low-grade ores. However, the slow growth rate and low biomass production of autotrophic bacteria commonly used in bioleaching limit their industrial application. Here, based on high-throughput sequencing analysis, which revealed a strong positive correlation between Sulfobacillus and Alicyclobacillus in mining environments, we developed a mixed-bacterial system composed of Sulfobacillus thermosulfidooxidans and Alicyclobacillus ferrooxydans to enhance the efficiency of bioleaching. The mixed-bacterial system achieved a pyrite leaching rate up to 91.14 %, compared to 67.54 % by S. thermosulfidooxidans and 17.63 % by A. ferrooxydans. The improved leaching performance was attributed to the increased production of total extracellular polymeric substances (EPS), higher cell density and stronger redox capacity in the bioleaching solution. This study contributes to the development of a greener and more sustainable metallurgical industry.