title: Improved biomass productivity in algal biofilms through synergistic interactions between photon flux density and carbon dioxide concentration.
abstract: Algal biofilms were grown to investigate the interaction effects of bulk medium CO2 concentration and photon flux density (PFD) on biomass productivities. When increasing the CO2 concentration from 0.04% to 2%, while maintaining a PFD of 100μmol/m(2)/s, biomass productivities increased from ∼0.5 to 2.0g/m(2)/d; however, the productivities plateaued when CO2 concentrations were incrementally increased above 2-12%. Statistical analysis demonstrates that there is a significant interaction between PFD and CO2 concentrations on biomass productivities. By simultaneously increasing PFD and CO2 concentrations, biomass productivities were significantly increased to 4.0 and 4.1g/m(2)/d in the experimental and modeled data, respectively. The second order model predicted increases in biomass productivities as both PFD and CO2 simultaneously increased yielding an optimum at 440μmol/m(2)/s and 7.1%; however, when conditions were extended to the highest end of their respective ranges, the conditions were detrimental to growth and productivities decreased.
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Schnurr
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.
authors.forename: Olivia
authors.initials: O
authors.lastname: Molenda
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; Department of Cell & Systems Biology, University of Toronto, Mississauga, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Edwards
authors.affiliation: Department of Cell & Systems Biology, University of Toronto, Mississauga, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada.
authors.forename: George S
authors.initials: GS
authors.lastname: Espie
authors.affiliation: Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada. Electronic address: dgrant.allen@utoronto.ca.
authors.forename: D Grant
authors.initials: DG
authors.lastname: Allen
mesh_terms: D018441:Biofilms / Q000254:growth & development* / Q000528:radiation effects; D018533:Biomass; D002245:Carbon Dioxide / Q000494:pharmacology*; D007700:Kinetics; D058086:Microalgae / Q000187:drug effects / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects; D008962:Models, Theoretical; D017785:Photons; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects
chemical_list: D002245:Carbon Dioxide
keywords: Biofilms; Carbon dioxide concentrations; Growth rates; Interaction effects; Microalgae; Photon flux density; Productivity