Figure 1: Schematic description of experimental design and quantitation of microbial communities in microcosms based on 16S rRNA gene copy number.

(a) Soil was serially diluted and inoculated to sterilized soil slurry microcosms subjected to metagenomic analysis and experiments. (b) Copy number of the 16S rRNA gene in the 10−2-inoculated samples and (c) 10−5-inoculated samples. C, control; D, diesel-spiked soil; DR, diesel-spiked soil and red clay; DP, diesel-spiked soil and processed red clay.