title: 16S rRNA Sequencing of microorganisms present in bioreactor using guar gum to stimulate biogenic sulfide production
design: Sequencing of PCR amplicons of 16S rRNA was conducted with the Illumina MiSeq platform (Illumina, San Diego, CA, USA) targeting the V4 hyper variable regions (forward primer, 515F, 5?-GTGYCAGCMGCCGCGGTAA-3?; reverse primer, 806R, 5?-GGACTACHVGGGTWTCTAAT-3?) for 2?×?150-bp paired-end sequencing (Illumina). PCR amplification was performed using Roche FastStart High Fidelity PCR System (Roche Diagnostics Ltd, Burgess Hill, UK) in 50?l reactions under the following conditions: initial denaturation at 95°C for 2?min, followed by 36 cycles of 95°C for 30?s, 55°C for 30?s, 72°C for 1 min, and a final extension step of 5?min at 72°C. The PCR products were purified and normalised to ~20ng each using the SequalPrep Normalization Kit (Fisher Scientific, Loughborough, UK). The PCR amplicons from all samples were pooled in equimolar ratios. The run was performed using a 4pM sample library spiked with 4pM PhiX to a final concentration of 10% following the method of Schloss and Kozich.