DX1
Total genome DNA of all sediment samples (1 g) and worm intestine samples (1 g) was extracted using the FastDNAspin kit (MP bio, Carlsbad, CA, USA) and QIAamp Fast DNA Stool Mini Kit (Qiagen, Germantown, WI, USA), respectively. The V3V4 region of the microbial 16S rRNA gene was amplified using specific primers with a barcode. The following primers were used: 341F (5-CCTAYGGGRBGCASCAG-3) and 806R (5-GGACTACNNGGGTATCTAAT-3). The PCR products were sequenced using an Illumina NovaSeq 6000, and 250-bp paired-end reads were generated. Paired-end reads from the original DNA fragments were merged as raw tags using FLASH (V1.2.11) (Chen et al., 2018). Paired-end reads were assigned to each sample according to the individual unique barcode. Raw tags of each sample were processed with QIIME 2 (V2020.2) to get clean tags under specific filtering conditions