Amplicon of archae: Karst wetland
Barcoded archaeal 16S rRNA gene amplicons were generated by amplifying the DNA samples using a set of 24 barcode-tagged archaea-specific 340F (CCCTAYGGGGYGCASCAG) - 1000R (GGCCATGCACYWCYTCTC) primers (Gantner, Andersson et al. 2011). The amplicons were around 660 bp in length, covering V3-V5 region and a partial V6 region of archaeal 16S RNA gene. Every amplification reaction was consisting of 10-50 ng of DNA template, 25 pmol of each primer, 4 l dNTP mixture (200 M), 5 g BSA, 1.5 U ExTaq DNA polymerase and 5 l 10Ex Taq Buffer (Takara Bio, China), and DNase-free ddH2O was added to reach a final volume of 50 l.All PCR were run in Bio-Rad T100 thermal cycler (Bio-Rad Laboratories, USA) with the following conditions: preincubation at 95 C for 2 min, followed by 10 cycles of denaturation at 95 C for 30 s, annealing at 51 C for 30 s, elongation at 72 C for 45 s and 25 cycles of 95 C for 30 s, 55 C for 30 s, 72 C for 45 s and a final extension step at 72 C for 7 min.