PT - JOURNAL ARTICLE AU - Ashish A. Malik AU - Bruce C. Thomson AU - Andrew S. Whiteley AU - Mark Bailey AU - Robert I. Griffiths TI - Bacterial physiological adaptations to contrasting edaphic conditions identified using landscape scale metagenomics AID - 10.1101/117887 DP - 2017 Jan 01 TA - bioRxiv PG - 117887 4099 - http://biorxiv.org/content/early/2017/03/18/117887.short 4100 - http://biorxiv.org/content/early/2017/03/18/117887.full AB - Environmental factors relating to soil pH are widely known to be important in structuring soil bacterial communities, yet the relationship between taxonomic community composition and functional diversity remains to be determined. Here, we analyze geographically distributed soils spanning a wide pH gradient and assess the functional gene capacity within those communities using whole genome metagenomics. Low pH soils consistently had fewer taxa (lower alpha and gamma diversity), but only marginal reductions in alpha diversity and equivalent gamma diversity. However, coherent changes in the relative abundances of annotated genes between pH classes were identified; with functional profiles clustering according to pH independent of geography. Differences in gene abundances were found to reflect survival and nutrient acquisition strategies, with organic-rich acidic soils harboring a greater abundance of cation efflux pumps, C and N direct fixation systems and fermentation pathways indicative of anaerobiosis. Conversely, high pH soils possessed more direct transporter-mediated mechanisms for organic C and N substrate acquisition. These findings show that bacterial functional versatility may not be constrained by taxonomy, and we further identify the range of physiological adaptations required to exist in soils of varying nutrient availability and edaphic conditions.