Figure 6: Photomicrographs of 1000x (1) phase contrast, (2) fluorescence of Nile red stained microalga viewed under excitation filter of 355–425 nm and emission filter of 470 nm, and (3) alternatively, excitation filter of 515–560 nm and emission filter of 590 nm of the 2-week old cultures. Red color, chlorophyll autofluorescence; yellow-gold fluorescence (excitation: 355–425 nm) or bright yellow fluorescence (excitation: 515–560 nm), lipid bodies. Samples were cultivated using (a) Walne’s photoautotrophic medium, (b) W-30 + 30 g/L glucose, and (c) ANN-based optimized medium.