2.5 | Bioinformatics analysis
To obtain high-quality clean reads, raw reads were demultiplexed and filtered for quality based on the methods developed by Fadrosh et al. (2014). Cleaned tags were obtained by FASTP (Chen et al., 2018). Sequences were assigned to operational taxonomic units (OTUs) based on a similarity cut-off of 97% by using UPARSE (v7.0.1090) (Edgar, 2013). The representative sequences from each OTU were then taxonomically classified using the Ribosomal Database Project (RDP) Classifier (v2.2) with confidence threshold of 80%.