Dataset: Peru Margin iTAGs

Peru Margin subsurface sediments were sampled on IODP leg 201 site 1229A (10°58.5721’ S 77°57.4590’W) in 150.5 m water depth. Core depth at 1229A was 187 mbsf.

DNA was extracted from either 2 or 20 grams of exterior and interior core sediment from frozen (stored at -80 degree C) Peru Margin samples collected at 6 mbsf (2H2) and 95 mbsf (11H5), respectively, using the PowerSoil DNA Isolation Kit (MoBio Laboratories, USA). Extractions were also performed for replicate samples collected from the exterior of both cores. The manufacturer’s protocol was modified to include five repetitions of homogenization for 1-minute intervals, with 1 minute rest in between, using a FastPrep benchtop homogenizer (MP Biomedicals, Santa Ana, CA) set to 4.0 m/s. A final purification step using isopropanol precipitation was also added. Duplicate extractions were performed for both interior and exterior regions of each core. Partial small-subunit ribosomal DNA (SSU rDNA) fragments were PCR amplified from DNA extracts using the key-tagged fungal-targeting primer set nu-SSU-0817-5’ and nu-SSU-1196-3’ (Borneman and Hartin, 2000). Replicate PCR amplifications (3-6) were run for each sample using Phusion High-Fidelity DNA Polymerase (ThermoFisher Scientific, USA) and 5X Phusion HF Buffer. PCR conditions were: 98 degrees C for 30 seconds followed by 40 cycles of 98 degrees C for 10 seconds, 56 degrees C for 30 seconds, and 72 degrees C for 30 seconds, and a final incubation for 7 minutes at 72 degrees C. PCR products were visualized by agarose gel electrophoresis and positive results were excised and purified from the gel using the ZymoClean Gel DNA recovery Kit (Zymo Research, USA). Purified replicate PCR amplifications from each sample were combined prior to iTAG sequencing using Illumina MiSeq PE300 at Georgia Genomics Center.