title: Kinetic modelling of growth and storage molecule production in microalgae under mixotrophic and autotrophic conditions.
abstract: In order to improve algal biofuel production on a commercial-scale, an understanding of algal growth and fuel molecule accumulation is essential. A mathematical model is presented that describes biomass growth and storage molecule (TAG lipid and starch) accumulation in the freshwater microalga Chlorella vulgaris, under mixotrophic and autotrophic conditions. Biomass growth was formulated based on the Droop model, while the storage molecule production was calculated based on the carbon balance within the algal cells incorporating carbon fixation via photosynthesis, organic carbon uptake and functional biomass growth. The model was validated with experimental growth data of C. vulgaris and was found to fit the data well. Sensitivity analysis showed that the model performance was highly sensitive to variations in parameters associated with nutrient factors, photosynthesis and light intensity. The maximum productivity and biomass concentration were achieved under mixotrophic nitrogen sufficient conditions, while the maximum storage content was obtained under mixotrophic nitrogen deficient conditions.
authors.affiliation: Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, United Kingdom. Electronic address: voa22@cam.ac.uk.
authors.forename: Victoria O
authors.initials: VO
authors.lastname: Adesanya
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Site, Cambridge CB2 3EA, United Kingdom.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Davey
authors.affiliation: Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, United Kingdom.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Scott
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Site, Cambridge CB2 3EA, United Kingdom.
authors.forename: Alison G
authors.initials: AG
authors.lastname: Smith
mesh_terms: D052818:Autotrophic Processes / Q000187:drug effects; D061249:Batch Cell Culture Techniques; D018533:Biomass; D048408:Chlorella vulgaris / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003198:Computer Simulation; D003470:Culture Media / Q000737:chemistry; D005947:Glucose / Q000494:pharmacology; D007700:Kinetics; D058086:Microalgae / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D008962:Models, Theoretical; D009584:Nitrogen / Q000494:pharmacology; D015203:Reproducibility of Results; D013213:Starch / Q000096:biosynthesis; D014280:Triglycerides / Q000378:metabolism
chemical_list: D003470:Culture Media; D014280:Triglycerides; D002734:Chlorophyll; D013213:Starch; D005947:Glucose; D009584:Nitrogen
keywords: Kinetic model; Microalgae; Mixotrophic; Starch; Triacyglycerides (TAG)