Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5478373 | Algal Research | 2017 | 10 Pages |
Abstract
The effect of flashing light and continuous light from red light emitting diodes on the photosynthetic activity of microalgae biofilms was investigated. In contrast to suspended microalgae cultures, biofilm-based microalgae photobioreactors allow a uniform exposure of the microalgae to incident radiation throughout the period of microalgae cultivation. In this work, multi-species microalgae biofilms were produced in a biofilm photobioreactor to be subsequently taken to an ad-hoc laboratory for biofilm light emitting diodes trials. Continuous light and flashing light at three light/dark frequencies: 0.1, 1 and 10 kHz and four light fractions: 5, 25, 50, and 75% were tested on microalgae biofilms. All flashing light experiments resulted in higher net photosynthetic activity of microalgae biofilms than the continuous light; the highest increase was obtained for 10 kHz frequency at 5% light fraction, for which the net photosynthetic activity was 7-times the continuous light (51 μmol photons mâ 2 sâ 1). Over the whole experiment, the quantum yield varied from 0.014 (at 10 kHz & 1 kHz, 766 μmol photons mâ 2 sâ 1) to 0.161 (at 10 kHz, 51 μmol photons mâ 2 sâ 1); the latter value was much higher than the theoretical maximum one, estimated at 0.125 μmol CO2 μmol photonsâ 1. Some hypotheses for this finding were raised, which would require further investigation.
Keywords
PGABPUFlashing light effectIRGAFLEChlNPALSDGLML/Dinfrared gas analyzerBiofilmphotosynthetic active radiationParlight/darkleast significant differenceLight emitting diodesLEDMicroalgaeChlorophyllGAPnet photosynthesisPhosphoglycerateGeneralized linear modelscontinuous lightFlashing lightlight fraction
Related Topics
Physical Sciences and Engineering
Energy
Renewable Energy, Sustainability and the Environment
Authors
Isabel MartÃn-Girela, MarÃa Dolores Curt, Jesús Fernández,