title: Stoichiometric modelling of assimilatory and dissimilatory biomass utilisation in a microbial community.
abstract: Assimilatory and dissimilatory utilisation of autotroph biomass by heterotrophs is a fundamental mechanism for the transfer of nutrients and energy across trophic levels. Metagenome data from a tractable, thermoacidophilic microbial community in Yellowstone National Park was used to build an in silico model to study heterotrophic utilisation of autotroph biomass using elementary flux mode analysis and flux balance analysis. Assimilatory and dissimilatory biomass utilisation was investigated using 29 forms of biomass-derived dissolved organic carbon (DOC) including individual monomer pools, individual macromolecular pools and aggregate biomass. The simulations identified ecologically competitive strategies for utilizing DOC under conditions of varying electron donor, electron acceptor or enzyme limitation. The simulated growth environment affected which form of DOC was the most competitive use of nutrients; for instance, oxygen limitation favoured utilisation of less reduced and fermentable DOC while carbon-limited environments favoured more reduced DOC. Additionally, metabolism was studied considering two encompassing metabolic strategies: simultaneous versus sequential use of DOC. Results of this study bound the transfer of nutrients and energy through microbial food webs, providing a quantitative foundation relevant to most microbial ecosystems.
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.|Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA.|Thermal Biology Institute, Montana State University, Bozeman, MT, USA.
authors.forename: Kristopher A
authors.initials: KA
authors.lastname: Hunt
authors.affiliation: Thermal Biology Institute, Montana State University, Bozeman, MT, USA.|Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA.
authors.forename: Ryan deM
authors.initials: RD
authors.lastname: Jennings
authors.affiliation: Thermal Biology Institute, Montana State University, Bozeman, MT, USA.|Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA.
authors.forename: William P
authors.initials: WP
authors.lastname: Inskeep
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.|Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA.|Thermal Biology Institute, Montana State University, Bozeman, MT, USA.
authors.forename: Ross P
authors.initials: RP
authors.lastname: Carlson
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D017753:Ecosystem; D056890:Eukaryota / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020387:Food Chain; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology*
chemical_list: D002244:Carbon