sequences of bacteria
Total soil DNA was extracted using the E.Z.N.A. Mag-Bind Soil DNA Kit (M5635-02, Omega, USA). The V3V4 region of bacterial 16S rRNA gene was amplified using primers 341F (5-CCTACGGGNGGCWGCAG-3) and 805R (5-CTACHVGGGTATCTAATCC-3). PCR products were purified, quantified with a Qubit 3.0 fluorometer, and sequenced on an Illumina MiSeq platform (paired-end, 2300 bp). Raw sequences were processed using CUTADAPT and QIIME 2.0, including quality filtering, denoising, and chimera removal. Taxonomic classification was performed with the RDP Classifier.