Attached culture of Nannochloropsis oculata for lipid production

The influences of urea, nitrate and glycine with four concentration levels on attached culture of Nannochloropsis oculata were investigated. The organic nitrogen source glycine was effective on improving not only adhesion biomass productivity but also adhesion rate. The maximum adhesion biomass productivity of 15.76 +/- A 0.52 g m(-2) day(-1) with adhesion rate of 76.67 +/- A 0.42 % was achieved with 18 mM glycine. To increase the lipid production, three lipid enhancing strategies were conducted afterwards, including nitrogen starvation, high light, and the combination of nitrogen starvation and high light. In nitrogen starvation situation, although the lipid content was greatly increased, the adhesion biomass productivity dropped probably due to the low cell viability. Increasing light intensity was effective on enhancing both adhesion biomass productivity and lipid content. The results indicated that nitrogen starvation was effective on improving both lipid content and adhesion rate when high light was applied. The maximum lipid yield of 4.32 +/- A 0.14 g m(-2) day(-1) with adhesion biomass productivity of 21.32 +/- A 0.65 g m(-2) day(-1), adhesion rate of 86.81 +/- A 0.10 % and lipid content of 20.24 +/- A 0.06 % was achieved with the combination strategy.