Microbial community succession patterns and assembly mechanisms in the white button mushroom (Agaricus bisporus) production with corn straw-based compost

The cultivation of Agaricus bisporus using corn straw as substrates effectively utilizes agricultural waste resources. This study analyzed the physicochemical properties and microbial succession of compost and casing substrates during A. bisporus cultivation with corn straw (wetting, thermophilic, pasteurization, spawning, casing, pinning, and harvesting). Microbiota underwent rapid succession during the wetting and thermophilic stages (78.2℃). After pasteurization (56.0℃), the wax layer-degrading microorganisms and mesophilic microorganisms were replaced by thermophilic lignocellulose-degrading microorganisms, Thermopolyspora , Thermomyces , and Mycothermus , forming a stable microbial community that can nourish and stimulate mushroom growth. These taxa decreased, and Chelatococcus increased during spawn run (25.0℃). Following the casing process (21.0℃), the microbial community composition changed significantly in compost, with Geobacillus becoming the dominant genus. Mushroom growth-promoting bacteria (MGPBs) Bradyrhizobium and Pseudomonas were key genera in the casing. Network analyses showed that organic materials were degraded mainly through microbial synergistic effect. Stochastic processes shaped the bacterial and fungal community assembly at all stages. The most crucial contributor influencing the succession of the bacterial and fungal communities in compost was the carbon-to-nitrogen ratio. In the casing layer, carbon and nitrogen were the key drivers of bacterial and fungal community succession, respectively. These findings provide a better understanding of microbial dynamics in corn straw-based mushroom cultivation systems, and they are valuable for optimizing environmentally friendly cultivation techniques that can generate ecological and health benefits. • Thermophilic lignocellulose-degrading organisms were predominant in mature compost. • Growth-promoting bacteria were the predominant groups in the casing layer. • Stochastic processes drove microbial community assembly in mushroom cultivation. • Carbon and nitrogen were the primary factors influencing microbial community.