Microbiota in a MPFLR anaerobic digester S1E
The V1-V3 hypervariable region (about 500 bp) of 16S rRNA gene was amplified from    each DNA sample using fusion primers ArcF-A and ArcR-B (for archaea) or BactF-A and     BactR-B (for bacteria) (Table 1). One hundred ng of each genomic DNA was used in each PCR     reaction with the following thermal program: initial denaturation at 95 °C for 5 min, followed     by 35 cycles of denaturing at 94 °C for 30 s, annealing at 54 °C for 30 s, and extension at 72 °C     for 1 min. The PCR cycles were ended with a final extension at 72 °C for 10 min. Quality of     the PCR products were examined using agarose gel (1.0 %) electrophoresis. The bands of the     expected size (approximately 550 bp) were excised and the DNA amplicons were purified    using a Qiaquick gel extraction kit (Qiagen, Valencia, CA). The purified amplicon libraries     were pooled at equimolar ratio to a final concentration of 20 ng DNA /µl for both bacteria and     archaea, and the two pools were then combined at a 9:1 molar ratio and sequenced using a Roche    GS FLX Titanium system at the Plant-Microbe Genomics Facility at The Ohio State University.