AUTHOR=Pepe-Ranney Charles , Campbell Ashley N. , Koechli Chantal N. , Berthrong Sean , Buckley Daniel H. 

TITLE=Unearthing the Ecology of Soil Microorganisms Using a High Resolution DNA-SIP Approach to Explore Cellulose and Xylose Metabolism in Soil

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00703

DOI=10.3389/fmicb.2016.00703

ISSN=1664-302X

ABSTRACT=<p>We explored microbial contributions to decomposition using a sophisticated approach to DNA Stable Isotope Probing (SIP). Our experiment evaluated the dynamics and ecological characteristics of functionally defined microbial groups that metabolize labile and structural C in soils. We added to soil a complex amendment representing plant derived organic matter substituted with either <sup>13</sup>C-xylose or <sup>13</sup>C-cellulose to represent labile and structural C pools derived from abundant components of plant biomass. We found evidence for <sup>13</sup>C-incorporation into DNA from <sup>13</sup>C-xylose and <sup>13</sup>C-cellulose in 49 and 63 operational taxonomic units (OTUs), respectively. The types of microorganisms that assimilated <sup>13</sup>C in the <sup>13</sup>C-xylose treatment changed over time being predominantly <italic>Firmicutes</italic> at day 1 followed by <italic>Bacteroidetes</italic> at day 3 and then <italic>Actinobacteria</italic> at day 7. These <sup>13</sup>C-labeling dynamics suggest labile C traveled through different trophic levels. In contrast, microorganisms generally metabolized cellulose-C after 14 days and did not change to the same extent in phylogenetic composition over time. Microorganisms that metabolized cellulose-C belonged to poorly characterized but cosmopolitan soil lineages including <italic>Verrucomicrobia, Chloroflexi</italic>, and <italic>Planctomycetes</italic>.</p>