Аңдатпа
ABSTRACT The extensive accumulation of coal gangue poses significant environmental threats through water contamination, soil degradation, and atmospheric pollution, necessitating the urgent development of ecological utilization strategies. This study elucidates the mechanistic basis by which the thermophilic bacterium Bacillus aerius ( B. aerius ) enhances plant growth in coal gangue-amended sandy soils. Through integrated analysis of nutrient dynamics, phytohormonal activities, soil enzymatic profiles, and metagenomic functional profiling, we demonstrate significant synergy between coal gangue and B. aerius . When applied together in sandy soils, the germination rate, plant height, root length, and fresh biomass of Medicago sativa (alfalfa) increased by 1.18–2.06 times. The levels of soil nitrogen, phosphorus, and potassium also significantly increased, resulting in notable improvements in soil fertility. The bacterial treatment enhanced the activities of indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and various soil enzyme activities while also optimizing the microbial community structure and increasing the abundance of beneficial bacteria, including Bacillus . Metagenomic analysis revealed the upregulation of growth-promoting genes such as acdS , nifK , and phnG , which collectively drive plant growth through multiple pathways, including enhanced soil nutrient availability, hormone regulation, soil enzyme activities, and nutrient cycling. Collectively, this work deciphers molecular-scale bacteria-gangue synergism, providing a theoretical foundation for sustainable coal gangue utilization and ecological restoration of degraded soils. IMPORTANCE The accumulation of coal gangue poses significant environmental challenges, necessitating the development of eco-friendly utilization strategies. This study demonstrates that the thermophilic bacterium Bacillus aerius acts synergistically with coal gangue to promote alfalfa growth in sandy soils while improving soil fertility. The combined treatment enhanced plant morphological traits, soil nutrient availability, beneficial microbial communities, and associated biological activities, with these effects supported by molecular evidence. As the first study to verify this growth-promoting mechanism, our findings address a critical knowledge gap and provide a theoretical foundation for the sustainable utilization of coal gangue in the ecological restoration of degraded soils.