Mapping the mcirobial food web with high resolution stable isotope probing

Soils make up one of the largest active carbon pools on the planet. Although carbon cycling in soil is mediated by microbial life, the microbial taxa that perform these major carbon transformations have not been well resolved.High-resolution stable isotope probing (HR-SIP) leverages multiplexed high-throughput 16S rRNA sequencing to simultaneously map in situ substrate assimilation dynamics for thousands of microbial taxa. We performed a HR-SIP experiment with nine 13C-labeled substrates representing organic matter present during plant biomass degradation (cellulose, xylose, glucose, glycerol, vanillin, palmitic acid, amino acids, lactate, and oxalate). These findings help to resolve the linkages between bacterial community structure and soil carbon cycling.