Fig. 3

Colonies and clusters of C. vulgaris in Day-4 160 mM NaHCO₃ culture (A); unicellular cells in pre-culture/cell size 1.85 ± 0.41 μm (A’), Day 2 160 mM NaCl culture/cell size 2.84 ± 0.70 (B’) and Day-2 160 mM NaHCO₃ culture/cell size 3.21 ± 0.73 μm (B); and colonies in Day-4 160 mM NaHCO₃ culture/colony size 4.24 ± 1.09 μm (C), and predominantly unicellular cells in Day 4 160 mM NaCl culture/cell size 2.23 ± 0.35 μm (C’). All micrographs were taken at 600 magnification except Graph A, which is the enlargement of part of Graph C. The red arrow in Graph A points to a colony in a cluster. Samples were diluted and then vortexed before microscopic examination for clarity when needed. Clusters as shown in Graph A were predominant in 160 mM NaHCO₃ cultures on Day 4 and thereafter