Comparison of Phospholipid Fatty Acid Profiles (PLFA) and a Combined qPCR-Pyrosequencing Approach to Assess Soil Microbial Community Composition.

Phospholipid fatty acids and 16S/18S rRNA pyrosequencing methods were used to analyze the soil microbial community associated with the rhizosphere of two different switch grass cultivars (Summer and Kanlo2) along a depth gradient.  Both techniques successfully detected differences in community abundance and composition due to both cultivar and soil depth.  The microbial community associated with the thinner roots of Summer had rhizodeposit C uptake associated primarily with saprotrophic fungi, while the thicker roots of Kanlow’s rhizodeposit C was processed primarily by G- bacteria. A detailed comparison of the methods will be presented.