title: Bacterial carbon use plasticity, phylogenetic diversity and the priming of soil organic matter.
abstract: Microorganisms perform most decomposition on Earth, mediating carbon (C) loss from ecosystems, and thereby influencing climate. Yet, how variation in the identity and composition of microbial communities influences ecosystem C balance is far from clear. Using quantitative stable isotope probing of DNA, we show how individual bacterial taxa influence soil C cycling following the addition of labile C (glucose). Specifically, we show that increased decomposition of soil C in response to added glucose (positive priming) occurs as a phylogenetically diverse group of taxa, accounting for a large proportion of the bacterial community, shift toward additional soil C use for growth. Our findings suggest that many microbial taxa exhibit C use plasticity, as most taxa altered their use of glucose and soil organic matter depending upon environmental conditions. In contrast, bacteria that exhibit other responses to glucose (reduced growth or reliance on glucose for additional growth) clustered strongly by phylogeny. These results suggest that positive priming is likely the prototypical response of bacteria to sustained labile C addition, consistent with the widespread occurrence of the positive priming effect in nature.
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.|Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA.
authors.forename: Ember M
authors.initials: EM
authors.lastname: Morrissey
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Mau
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.|Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: Egbert
authors.initials: E
authors.lastname: Schwartz
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.|Department of Biological Sciences, Colorado Mesa University, Grand Junction, CO, USA.
authors.forename: Theresa A
authors.initials: TA
authors.lastname: McHugh
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.|Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Dijkstra
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Koch
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.|Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: Jane C
authors.initials: JC
authors.lastname: Marks
authors.affiliation: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA.|Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Hungate
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D017753:Ecosystem; D014644:Genetic Variation; D010802:Phylogeny; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D012987:Soil; D002244:Carbon