I have got miseq data for 16S rRNA In this I have some over represented sequences(shown in fastqc) which does not have proper Barcodes/Primers labelled to it. These over represented sequences are "TGGAATTCTCGGGTGCCAAGGAACTCCAGTCACATGTCAATCTCGTATGC" and "GATCGTCGGACTGTAGAACTCTGAACGTGTAGATCTCGGTGGTCGCCGTA". I extracted these sequences from fastq file and tried blast and RDP classifier to identify what it is but didn't get any hit. If someone have faced the same issue can enlighten me what these sequences are?
Thank you,
Best,
Richa