Metabolomics data of ”Shifts in the bacterial population and ecosystem functions in response to vegetation in the Yellow River Delta wetlands“

Soil metabolomic analysis was performed using HPLC-MS/MS. Fresh soil samples were immediately frozen in liquid nitrogen, freeze dried, and then ground to powder. Approximately 100 mg of each sample was combined with 0.5 ml of 80% aqueous methanol (0.1% formic acid), shaken well, placed on ice for 5 min, and then centrifuged at 15000 rpm for 10 min at 4°C. The supernatant was diluted to 60% aqueous methanol, and then the samples were filtered using a 0.22 μm membrane.The soil metabolic profiles were determined on a Vanquish UHPLC system (Thermo Scientific, USA) coupled with a QE-HF-X mass spectrometer (Thermo Scientific, USA). A Hyperil Gold column (C18) at 40°C was used for chromatographic separation. The mobile phase included solvent A1 (positive ion mode, LC-grade pure water with 0.1% formic acid) or solvent A2 (negative ion mode, LC-grade pure water with 5.0 mM ammonium acetate, pH 9.0) and solvent B (methanol) at a rate of 0.2 ml/min. The solvent B gradient was changed as follows: 2.0% (0–1.5 min), 2.0-100% (1.5–12 min), 100% (12-14 min) and 2.0% (14-16 min). The mass spectrometer was operated in positive/negative polarity mode with a spray voltage of 3.2 kV, capillary temperature of 320°C, sheath gas flow rate of 35 arb and aux gas flow rate of 10 arb.