Changes in soil microbial diversity and composition across a ph gradient revealed through fingerprinting and illumina sequencing of ribosomal dna

We sampled from agricultural field plots that have been maintained at defined pH values since 1961 (Craibstone, Scotland) and employed both 16S rRNA gene fingerprinting and ultra-deep Illumina sequencing approaches to generate complementing datasets to investigate the influence of pH. Fourteen composite soil samples (seven each from 2006 and 2007, respectively) were taken from across an artificially maintained pH gradient (pH 4.5-7.5) and used to construct 200-base 16S rRNA gene libraries of ~500,000 sequences each.