design: Pre-incubation DNA extractions of the initial soil (250 mg) were performed using the DNeasy PowerSoil Pro Kit followed by a step to concentrate the DNA with the DNA Clean & Concentrator-5. The V3/V4 region of the 16S rRNA gene was amplified using the universal primers 515F and 806R. Thermal cycling consisted of initial denaturation at 95 C for 6 min, followed by 35 cycles of 95 C for 20 s, 55 C for 15 s, 72 C for 10 s and finally 72 C for 60 s using a thermal cycler. The PCR products were purified using the GeneRead Size Selection Kit. The concentration of DNA in the amplicons was measured using a micro volume spectrophotometer. Sequencing was conducted at the Illumina MiSeq platform.