The synergistic interaction of fungi with different structural characteristics improves the leaching of lithium from lepidolite

The aim of this study was to explore the improvement of lithium leaching from lepidolite by microbial co-culture, focusing on the synergistic effect of different structural fungi in improving the leaching performance of biological systems. The results showed that in the single leaching experiment, the multicellular fungi and the unicellular yeast showed weak effects. Multicellular fungus is limited by insufficient EPS secretion, while unicellular yeast is non-mycelial organisms with weak acid production capacity and limited effect on minerals. However, in the combined leaching experiment, the interspecific collaboration promoted the synthetic and metabolic activity of the two strains, resulting in changes in the type and content of organic acids, polysaccharides, proteins and humus. The content of citric acid reached the highest value of 16.98 g·L⁻¹ at about 22 d, and the EPS secreted by unicellular yeast promoted the mycelium adhesion and mineral wrapping of multicellular fungi. The combined action of the two enhanced the effects of acidification, complexation and mycelium destruction, and improved the leaching effect. This study revealed the synergistic metabolic mechanism of lepidolite leaching by fungi with different structures, verified the effectiveness of microbial co-culture to improve the leaching rate, and provided a basis for industrial application. In addition, the use of co-culture technology has a positive impact on commercial production and environmental protection.