title: Effect of the temperature, pH and irradiance on the photosynthetic activity by Scenedesmus obtusiusculus under nitrogen replete and deplete conditions.
abstract: This paper evaluates the effect of the irradiance, pH and temperature on the photosynthetic activity (PA) of Scenedesmus obtusiusculus under N-replete and N-deplete conditions through oxygen measurements. The highest PA values were 160 mgO2 gb(-1) h(-1) at 620 μmol m(-2) s(-1), 35 °C and pH of 8 under N-replete conditions and 3.3 mgO2 gb(-1) h(-1) at 100 μmol m(-2) s(-1), 28.5 °C and pH of 5.5 for N-deplete conditions. Those operation conditions were tested in a flat-panel photobioreactor. The biomass productivity was 0.97 gb L(-1) d(-1) under N-replete conditions with a photosynthetic efficiency (PE) of 4.4% yielding 0.85 gb mol photon(-1). Similar biomass productivity was obtained under N-deplete condition; and the lipid productivity was 0.34 gL L(-1) d(-1) with a PE of 7.8% yielding 0.39 gL mol photon(-1). The apparent activation and deactivation energies were 16.1 and 30 kcal mol(-1), and 11.9 and 15.3 kcal mol(-1), for N-replete and N-deplete conditions, respectively.
authors: Doctorado en Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, Mexico.
authors: Juan
authors: J
authors: Cabello
authors: Doctorado en Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Mexico.
authors: Alma
authors: A
authors: Toledo-Cervantes
authors: Doctorado en Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, Mexico.
authors: León
authors: L
authors: Sánchez
authors: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Mexico.
authors: Sergio
authors: S
authors: Revah
authors: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Mexico. Electronic address: mmorales@correo.cua.uam.mx.
authors: Marcia
authors: M
authors: Morales
mesh_terms: D018533:Biomass; D006863:Hydrogen-Ion Concentration; D008027:Light; D008055:Lipids / Q000096:biosynthesis; D009584:Nitrogen / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects / Q000528:radiation effects; D010100:Oxygen / Q000378:metabolism; D058433:Photobioreactors / Q000382:microbiology; D010788:Photosynthesis / Q000187:drug effects* / Q000528:radiation effects*; D044444:Scenedesmus / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D013696:Temperature
chemical_list: D008055:Lipids; D009584:Nitrogen; D010100:Oxygen
keywords: Apparent activation energy; Lipid accumulation; Photobioreactors; Photosynthetic activity; Scenedesmus obtusiusculus