Comparing Harvest Productivity of the Filamentous Alga Oedogonium with Microalgae

Abstract

As the planet is faced with depletion of its natural resources, alternative and sustainable energy sources are becoming increasingly sought after.  Research on the growth of algae has revealed their potential for carbon capture to reduce greenhouse gas emissions and for conversion into a fuel source for bioenergy applications.  Filamentous algae have attracted recent attention as an optimal species due to their ease of harvest and dominance over other species.  To determine the most suitable species for future biomass applications, a 1000-L open raceway pond was inoculated with the freshwater filamentous alga, Oedogonium.  The pond culture was harvested weekly to determine the effects of CO2 addition on culture density (mg VSS/L) and harvest productivity (g VSS/m2-day).  An additional two 1000-L raceway ponds with established cultures of microalgae already receiving CO2 were used as a comparison to the growth of Oedogonium.  After 3 weeks, Oedogonium harvest productivity exceeded both microalgal ponds at 13.7 (± 0.2) g VSS/m2-day compared to 9.3 (± 0.7) and 9.5 (± 0.3) g VSS/m2-day for the microalgae.