The Response of Substrate Microbial Communities to the Addition of Mineral Nutrients During the Growth Period of Straw Mushroom Volvariella volvacea

<i>Volvariella volvacea</i> were grown on an abandoned cotton-based substrate, which was divided into two conditions: a group with added nutrients (N3P3) and a control group (CK). Using metagenomic sequencing technology, the study investigated the effect of nutrient addition during the growth process of <i>V. volvacea</i> on the microbial community and metabolic pathways of the substrate. The study found that the main bacteria in the N3P3 group were <i>Proteus</i> and <i>Microsporidium</i>, while in the CK group, <i>Bacillus marinosus and Microsporidium globosa</i> were more common. At all stages of <i>V. volvacea</i> growth, <i>Proteobacteria</i> and <i>Firmicutes</i> dominated. Metabolic function analysis showed that the N3P3 group significantly increased amino acid metabolism, nitrogen metabolism, genetic information processing, and cellular processes, while reducing the contents of pathogenic and saprophytic symbiotic fungi. Nitrogen metabolism, phosphorus metabolism, and carbon metabolism were closely related to the growth of <i>V. volvacea</i>, and nutrient addition significantly improved microbial community diversity and metabolic levels, which can be used as a substrate optimization formula. This is of great significance for the development of sustainable agriculture.