title: Lumped pathway metabolic model of organic carbon accumulation and mobilization by the alga Chlamydomonas reinhardtii.
abstract: Phototrophic microorganisms have significant potential as bioenergy feedstocks, but the sustainability of large-scale cultivation will require the use of wastewater as a renewable resource. A key barrier to this advancement is a lack of bioprocess understanding that would enable the design and implementation of efficient and resilient mixed community, naturally lit cultivation systems. In this study, a lumped pathway metabolic model (denoted the phototrophic process model or PPM) was developed for mixed phototrophic communities subjected to day/night cycling. State variables included functional biomass (XCPO), stored carbohydrates (XCH), stored lipids (XLI), nitrate (SNO), phosphate (SP), and others. PPM metabolic reactions and stoichiometry were based on Chlamydomonas reinhardtii , but experiments for model calibration and validation were performed in flat panel photobioreactors (PBRs) originally inoculated with biomass from a phototrophic system at a wastewater treatment plant. PBRs were operated continuously as cyclostats to poise cells for intrinsic kinetic parameter estimation in batch studies, which included nutrient-available conditions in light and dark as well as nitrogen-starved and phosphorus-starved conditions in light. The model was calibrated and validated and was shown to be a reasonable predictor of growth, lipid and carbohydrate storage, and lipid and carbohydrate mobilization by a mixed microbial community.
authors: Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
authors: Jeremy S
authors: JS
authors: Guest
authors: Mark C M
authors: MC
authors: van Loosdrecht
authors: Steven J
authors: SJ
authors: Skerlos
authors: Nancy G
authors: NG
authors: Love
mesh_terms: D002138:Calibration; D002244:Carbon / Q000378:metabolism*; D016825:Chlamydomonas reinhardtii / Q000254:growth & development / Q000378:metabolism*; D007700:Kinetics; D050356:Lipid Metabolism; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D009930:Organic Chemicals / Q000378:metabolism*; D058433:Photobioreactors; D052817:Phototrophic Processes; D015203:Reproducibility of Results
chemical_list: D009930:Organic Chemicals; D002244:Carbon