title: Response of bacterioplankton to silver nanoparticle additions in wetland mesocosms
design: We extracted DNA using the Gentra Puregene Yeast/Bact. Kit (Qiagen) according to the manufacturer s instructions supplemented with three rounds of bead beating (60 seconds each).  Microbial communities were characterized using a dual index approach with the following portions of the primer targeting the V3/V4 region of the bacterial and archaeal 16S rRNA gene: S-D-Bact-0341-b-S-17 (16S F V3; CCTACGGGNGGCWSCAG) and Arch806  (16S R V4; GGACTACNVGGGTWTCTAAT).