Abstract：
Numerous studies have demonstrated that the co-leaching of ores by different silicate bacteria significantly improves the performance of bioleaching systems. Nevertheless, the mechanism of different silicate bacteria synergistically or complementarily enhanced the leaching process of lithium-containing silicate remains unclear. This study discussed the leaching impact of the combined presence of two metabolically distinct silicate bacteria on lepidolite, with the aim of comprehending the synergistic effect resulting from the presence of Bacillus mucilaginosus and Bacillus circulans in the leaching process. The results indicated that the polysaccharides and proteins secreted by bacteria-containing functional groups such as -OH and -COOH, which played an important role in the complex decomposition of ores. Organic acids played the role of acid etching and complexation. Bacillus mucilaginosus and Bacillus circulans exhibited low individual leaching efficiency, primarily due to their weak organic acid secretion. Moreover, the prolific polysaccharide production by Bacillus mucilaginosus led to bacterial aggregation, diminishing contact capability with minerals. Bacillus circulans decomposed the excessive polysaccharides produced by Bacillus mucilaginosus through enzymatic hydrolysis in the co-bioleaching process, providing later nutrient supply for both strains. The symbiosis of the two strains enhanced the synthesis and metabolic capabilities of both strains, resulting in increased organic acid secretion. In addition, protein and humic acid production by Bacillus mucilaginosus intensified, collectively enhancing the leaching efficiency. These findings suggested that the primary metabolic products secreted by different bacterial strains in the leaching process differ. The improvement in bioleaching efficiency during co-leaching was attributed to their effective synergistic metabolism. This work contributes to the construction of an efficient engineering microbial community to improve the efficiency of silicate mineral leaching, and reveals the feasibility of microbial co-culture to improve bioleaching.
摘要：
大量研究表明，不同硅酸盐细菌对矿石的共浸出显着提高了生物浸出系统的性能。然而，不同硅酸盐细菌协同或互补增强含锂硅酸盐浸出过程的机理尚不清楚。本研究讨论了两种代谢不同的硅酸盐细菌的组合存在对锂云母的浸出影响，目的是理解在浸出过程中由于粘液芽孢杆菌和环状芽孢杆菌的存在而产生的协同作用。结果表明，细菌分泌的多糖和蛋白质含有官能团，如-OH和-COOH，在复杂的矿石分解中起着重要作用。有机酸起着酸蚀和络合作用。粘液芽孢杆菌和环状芽孢杆菌表现出较低的个体浸出效率，主要是由于它们的有机酸分泌弱。此外，粘液芽孢杆菌生产的多产多糖导致细菌聚集，与矿物的接触能力减弱。环状芽孢杆菌在共浸出过程中通过酶水解分解了胶质芽孢杆菌产生的过量多糖，为这两种菌株提供后期营养供应。两个菌株的共生增强了两个菌株的合成和代谢能力,导致有机酸分泌增加。此外,胶质芽孢杆菌产生的蛋白质和腐殖酸增强，集体提高浸出效率。这些发现表明，不同菌株在浸出过程中分泌的主要代谢产物不同。共浸出过程中生物浸出效率的提高归因于它们的有效协同代谢。这项工作有助于构建高效的工程微生物群落，以提高硅酸盐矿物的浸出效率，并揭示了微生物共培养提高生物浸出的可行性。
