Ambient_Controls_chamber_57
primer pairs targeting the V3-V4 hypervariable region of the bacterial 16S rRNA gene (Klindworth et al., 2013; 314F, 5- CCTACGGGNGGCWGCAG-3; and 805R, 5-GACTACHVGGGTATCTAATCC-3) and a standard single-step PCR procedure.