title: Carbon dioxide consumption of the microalga Scenedesmus obtusiusculus under transient inlet CO2concentration variations.
abstract: The extensive microalgae diversity offers considerable versatility for a wide range of biotechnological applications in environmental and production processes. Microalgal cultivation is based on CO2fixation via photosynthesis and, consequently, it is necessary to evaluate, in a short time and reliable way, the effect of the CO2gas concentration on the consumption rate and establish the tolerance range of different strains and the amount of inorganic carbon that can be incorporated into biomass in order to establish the potential for industrial scale application. Dynamic experiments allow calculating the short-term microalgal photosynthetic activity of strains in photobioreactors. In this paper, the effect of step-changes in CO2concentration fed to a 20L bubble column photobioreactor on the CO2consumption rate of Scenedesmus obtusiusculus was evaluated at different operation times. The highest apparent CO2consumption rate (336μmolm-2s-1and 5.6% of CO2) was 6530mgCO2gb-1d-1and it decreased to 222mgCO2gb-1d-1when biomass concentration increased of 0.5 to 3.1gbL-1and 5.6% of CO2was fed. For low CO2concentrations (<3.8%) the pH remained close to the optimal value (7.5 and 8). The CO2consumption rates show that S. obtusiusculus was not limited by CO2availability for concentrations above of 3.8%. The CO2mass balance showed that 90% of the C-CO2transferred was used for S. obtusiusculus growth.
authors.affiliation: Departamento de Ingeniería de Procesos e Hidráulica, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, C.P. 09340 Cd. de México, Mexico.
authors.forename: Juan
authors.initials: J
authors.lastname: Cabello
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Colonia Santa Fe Cuajimalpa, C.P. 05300 Cd. de México, Mexico. Electronic address: mmorales@corrreo.cua.uam.mx.
authors.forename: Marcia
authors.initials: M
authors.lastname: Morales
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Colonia Santa Fe Cuajimalpa, C.P. 05300 Cd. de México, Mexico. Electronic address: srevah@correo.cua.uam.mx.
authors.forename: Sergio
authors.initials: S
authors.lastname: Revah
mesh_terms: D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism*; D058086:Microalgae / Q000378:metabolism; D058433:Photobioreactors; D044444:Scenedesmus / Q000378:metabolism*
chemical_list: D002245:Carbon Dioxide
keywords: CO(2) consumption rate; Photobioreactors; Photosynthetic activity; Scenedesmus