Developing Microalgae as Production Platforms for Natural Products /
- Author(s): Schoepp, Nathan;
- et al.
Microalgae and cyanobacteria have recently reemerged as a potential crop in the effort to abate continually increasing issues of sustainability in the production of food and fuel. In a field where substantial discrepancies consistently exist between laboratory and outdoor cultivation, gains in the development of laboratory technologies have in general not been paralleled with field demonstrations. For these reasons, we developed a low-maintenance system and process for research-scale outdoor cultivation of a variety of both freshwater and marine eukaryotic microalgae and cyanobacteria. Scenedesmus, Chlorella, Chlamydomonas, Arthrospira, Anabaena, Porphyridium, Nannochloropsis, Dunaliella, and Phaeodactylum were tested in the system, and demonstrate the growth of both model and commercial-production organisms. Biomass densities ranging from 0.30 g/L - 0.73 g/L were obtained in 100 L hanging polybags, with similar densities of 0.16 g/L - 0.82 g/L achieved during outdoor autotrophic growth in 800 L airlifted stock-ponds. Total capital expenses of the stock-pond system were under $4000 dollars, with ongoing production costs ranging from 0.04 $ /g - 0.27 $/g. Depending on the strain cultivated, hundreds to thousands of grams of dry biomass could be produced in a single growth cycle in the stock-ponds, suitable for a variety of uses including inoculum generation, recombinant protein production, natural product isolation, and biofuel applications. Following testing in the stock-ponds, Scenedesmus dimorphus (UTEX 1237) was grown semi-continuously in an 8,000 L airlift- driven raceway, yielding over eight kilograms of dry biomass