|Title||Antenna size reduction in microalgae mass culture|
|Author(s)||Mooij, T. de|
|Source||University. Promotor(en): Rene Wijffels, co-promotor(en): Marcel Janssen. - Wageningen : Wageningen University - ISBN 9789462578890 - 196 p.|
|Publication type||Dissertation, internally prepared|
|Keyword(s)||algae culture - algae - light - photobioreactors - photosynthesis - mutants - algenteelt - algen - licht - fotobioreactoren - fotosynthese - mutanten|
|Categories||Food and Bioprocess Engineering (General) / Algae|
The thesis describes the potential of microalgae with a reduced light harvesting antenna for biomass production under mass culture conditions (high biomass density, high light intensity). Theoretically, the lower chlorophyll content reduces the light harvesting capacity and with that the amount of photosaturation. The result would be an increase of the biomass yield on light energy, which is especially favorable at high light intensities. In practice, it was found that the productivity of several antenna size mutants strains was equal, or even lower than that of wild type microalgae. The genetically modified algae suffered from a reduced fitness, possibly because the antenna alterations led to impaired photoprotection mechanisms. In an alternative approach, it was found that by spectral tuning (applying different light colours) oversaturation was decreased and the productivity of wild type microalgae was increased. Special attention was paid to photoacclimation behavior of wild type microalgae. It was investigated whether ‘natural acclimation’ can be exploited to maximize productivity. In the last chapter, the competition between antenna size mutants and wild type cells is investigated by means of a modeling approach. It became clear that a wild type infection of an antenna size mutant culture should be prevented at all costs, as the mutants have a reduced competitive strength.