title: Luminostat operation: a tool to maximize microalgae photosynthetic efficiency in photobioreactors during the daily light cycle?
abstract: The luminostat regime has been proposed as a way to maximize light absorption and thus to increase the microalgae photosynthetic efficiency within photobioreactors. In this study, simulated outdoor light conditions were applied to a lab-scale photobioreactor in order to evaluate the luminostat control under varying light conditions. The photon flux density leaving the reactor (PFD(out)) was varied from 4 to 20 μmol photons m(-2)s(-1)and the productivity and photosynthetic efficiency of Chlorella sorokiniana were assessed. Maximal volumetric productivity (1.22g kg(-1)d(-1)) and biomass yield on PAR photons (400-700 nm) absorbed (1.27 g mol(-1)) were found when PFD(out) was maintained between 4 and 6 μmol photons m(-2)s(-1). The resultant photosynthetic efficiency was comparable to that already reported in a chemostat-controlled reactor. A strict luminostat regime could not be maintained under varying light conditions. Further modifications to the luminostat control are required before application under outdoor conditions.
authors.affiliation: Wageningen University, Bioprocess Engineering, P.O. Box 8129, 6700 EV, Wageningen, The Netherlands. maria.cuaresma@wur.nl
authors.forename: María
authors.initials: M
authors.lastname: Cuaresma
authors.forename: Marcel
authors.initials: M
authors.lastname: Janssen
authors.forename: Evert Jan
authors.initials: EJ
authors.lastname: van den End
authors.forename: Carlos
authors.initials: C
authors.lastname: Vílchez
authors.forename: René H
authors.initials: RH
authors.lastname: Wijffels
mesh_terms: D018533:Biomass; D019149:Bioreactors; D008027:Light; D058086:Microalgae / Q000502:physiology*; D010777:Photochemistry; D010788:Photosynthesis