Fig. 1
From: Nitrogen and phosphorus stress as a tool to induce lipid production in microalgae
Projection of the studied variables and observations onto the factorial plane PC 1 and PC 2 for Cyanobacteria. Indicators (variables): light intensity (µmol photons m− 2 s− 1); cultivation time (days); lipid content (% DW); lipid productivity (mg L− 1 day− 1); total nitrogen (g L− 1); total phosphorus (g L− 1); N:P (unit). Observations: species or strain numbers (circles): Arthrospira platensis (1–4); Arthrospira platensis NIOF17/003 (5); Microcystis aeruginosa (6, 16, 17); Microcystis aeruginosa CACIAM08 (7–13); Microcystis aeruginosa NPCD-1 (14, 15); Oscillatoria sp. PBGA3 (18); Synechococcus elongatus PCC7942 (19); Synechocystis sp. CACIAM05 (20–26); Synechocystis sp. MH01 (27); Tolypothrix sp. PBGA1 (28); Tolypothrix sp. PBGA2 (29); Trichormus sp. CENA77 (30). Group A: species and strains representing filamentous Cyanobacteria (Arthrospira, Oscillatoria, Tolypothrix). Group B: species and strains representing coccoid Cyanobacteria (Microcystis, Synechococcus, Synechocystis). Red circles (here and further) unite species and strains of microalgae, which are characterised by general patterns (groups A, B) in the coordinate space specified by PC 1 and PC 2