The Relationship between Material Transformation, Microbial Community and Amino Acids and Alkaloid Metabolites in the Mushroom Residue Composting With Biocontrol Agent Addition

This study investigated the effects of adding biocontrol microbes on metabolites and pathogenic microorganisms during mushroom residue composting and the relationships between metabolite changes and microbes and material transformation. The results showed that co-composting of Bacillus subtilis (BS) and Trichoderma harzianum (TH) with mushroom residue promoted the conversion of organic carbon and nitrogen. Thirteen plant pathogenic fungi genera were eliminated or had decreased abundance in biocontrol microbial treatments. BS or TH treatments increased the levels of amino acids, carbohydrates, and bacteriostatic alkaloid metabolites. Network analysis revealed that the main microorganisms significantly related to alkaloid metabolites were Rhabdanaerobium, Atopostipes, Planifilum and Ureibacillus. The increased bacterial abundance and decreased NO3--N and TOC were the main reasons for the increases in amino acid and alkaloid metabolites after biocontrol agent treatments. Generally, co-composting with biocontrol microbes is an effective way to increase the levels of antibacterial metabolites and eliminate plant pathogenic fungi in compost.