Fluorescence Transients as a Selection Tool for Marine Microalgal Consortia in a Raceway Pond Reactor for Biofuel Production

Abstract

In the search for renewable fuels, microalgae are seen as a potential source of oil that can be cultivated at large scale without competing with terrestrial food agriculture. Among the unsolved problems in the large scale production of microalgae for biofuel, is a rapid selection process based on lipid productivity. The fluorescence transients of consortia can be used as a measure of its lipid yield, thereby providing faster selection criteria. In order to test this hypothesis, a continuous (part harvested daily) raceway pond reactor with perpetual flocs containing microalgae consortia was developed. It is possible to select the dominant microalgal strains in the consortium by changing the process conditions. In this approach, process conditions that lead to higher lipid yield are desired. In this paper the photosynthetic activity of components of the algal consortia is measured by fluorescence transients and compared with lipid yield. It was found that, in our culture, brown microalga diatom dominant association had higher photosynthetic efficiency than a green filamentous microalgae association, and had higher lipid content