title: sequences of bacteria
design: The DNA fragments of the community were subjected to Paired-end sequencing using the Illumina MiSeq platform. The sequencing raw data is saved in the FASTQ format. First, the sliding window method is used to screen the double-ended sequences of the FASTQ format one by one, with a window size of 10 bp and a step size of 1 bp. Using the FLASH software, pairing the double-ended sequences that have been sieved by mass, the conditions of the bases are well-matched. Next, the overlapping base lengths of the two sequences of Read 1 and Read 2 are required to be  10 bp. Finally, the valid sequence is identified according to the Index information (ie, the Barcode sequence) corresponding to each sample (requires the Index sequence to match exactly). Identify the question sequence using QIIME software (Quantitative Insights Into Microbial Ecology, v1.8.0, http://qiime.org/) and call it USEARCH (v5.2.236, http://www.drive5 .com/usearch/) Check and reject chimeric sequences to gain high quality sequences that can be used for following analysis.