Soil Sample Processing and Metabolomics

For detailed methods of soil sample processing and secondary metabolite detection, we refer to our previously published paper [3 (link)]. In order to increase the accuracy of the entire analysis, we also included one quality control (QC) sample for every 10 samples. The QC sample was prepared by mixing the extracts of all samples in the same amount, and each QC sample was the same amount as the tested sample. Analysis of GC-MS metabolomics of soil samples was conducted on Agilent Technologies Inc. 7890B-5977A GC/MSD GC-MS (Santa Clara, CA, USA), which was carried out, as described in our recent publication [3 (link)]. Furthermore, the metabolite information was obtained by analyzing the KEGG database after comparing the data obtained in this study with the standard spectrum library.