title: 16S amplicon of microbial community : negative control
design: Project BIOKARST : sampling of microbial communities on artificial substrates (clay beads) and sediments in karstic aquifers (Bauges), chemical lysis followed by extraction with DNeasy PowerSoil Pro Kit of Qiagen, first amplification of a region of the rRNA 16S gene with 515F-Y/926R primer pair  (5-GTGYCAGCMGCCGCGGTAA-3/5-CCGYCAATTYMTTTRAGTTT-3), second amplification to add Illumina adaptors, sequencing 2*250 PE (MiSeq6-M07093, Genotoul), Illumina MiSeq Reagent Kit v3