The Effect of Nitrogen Deficiency on the Growth and Lipid Content of Isochrysis affinis galbana in Two Photobioreactor Systems (PBR): Tubular and Flat Panel

Abstract

Energy is becoming one of the most expensive production inputsnowadays. Energy reserves are starting to run out and their pollutingnature has become undeniable. Therefore, there is an urgentnecessity for renewable energies. One of these energy sources isalgae, which are seen as promising for biofuel production. Algaecan be cultured in non-agricultural land, high photosyntheticactivity, harvested throughout the year high biomass production.High lipid from algae is possible by reducing some elements ofgrowth conditions from the nutrient medium. In this study,Isochrysis affinis galbana species were cultured in two reactors; flatpanel photobioreactors with different light paths (1, 3, 5, 7 and 10cm) and tubular photobioreactors, with 50% nitrogen reduction and20% inoculation densities. Biomass, lipid and protein ratios weredetermined. The highest lipid content of 33.13% was obtained fromI. aff. galbana with 12.11% protein in flat panel photobioreactorswith 50% nitrogen reduction and 10 cm light path, and a 0.991 g L-1biomass rate was obtained. The highest optical density was found inthe 10 cm light path flat panel photobioreactor with a 50% nitrogenreduction.