Neochloris oleoabundans Growth Evaluation Under Different Nitrogen:Phosphorus:Carbon Feeding Strategies

Microalgae are photosynthetic microorganisms known for their variety of compounds that can be useful for food, feed, pharmaceuticals, and fuel industries. Microalgae production costs have been one of the major obstacles to large-scale commercial production. Therefore, several studies are still being performed aiming to increase biomass by developing novel photobioreactor design and microalgae cultivation techniques. This work's purpose is to increase Neochloris oleoabundans biomass. Different nutrient-feeding regimes were tested in N. oleoabundans cultivation in Erlenmeyer flasks and bench-scale tubular photobioreactor. In Erlenmeyer flasks, the best concentrations of nitrate and phosphate were 8.82 mM and 5.16 mM, respectively. In bench-scale tubular photobioreactor, NaNO₃ proved to be the best nitrogen source, in comparison with (NH₄)₂SO₄ and NH₄NO₃. Still in the photobioreator, the addition of nitrate by fed-batch process combined with automated system of CO₂ feeding showed to be of utmost importance for insuring a high density of N. oleoabundans. The essential nutrients evaluated in this work play an important role on N. oleoabundans biomass accumulation, as well as the photobioreactor configuration and feeding regimes.