Figure 7
Effect of the NaCl stress and CuSO4 stress on the Synechocystis-fungi flocculation. Total biomass is the sum of flocculated and suspended biomasses. Values are shown as the mean ± 1SD (n = 4). LD: low detection level at < 2 mg/L of the flocculated biomass or < 0.5% of percent flocculated biomass per total biomass. (a) Effect of the NaCl stress. Co-cultivation between Synechocystis (fixed initial cell density of OD730 = 0.2) and the fungi (fixed initial fungi inoculation of 5 mg fresh weight/100 mL) in the presence of NaCl at 1 or 2 M for 7 days. Culture: representative images of the culture flasks. (b) Effect of the CuSO4 stress. Co-cultivation between Synechocystis (fixed initial cell density of OD730 = 0.2) and the fungi (fixed initial fungi inoculation of 5 mg fresh weight/100 mL) in the presence of CuSO4 at 4 or 8 µM for 7 days. Culture: representative images of the culture flasks. Microscope: Synechocystis-fungi flocculated biomass as seen by bright-field microscopy (BF, left) and fluorescent microscopy (FL, right) showing the red light resulting from auto-fluorescence of Synechocystis chlorophyll. (c) The cultivation of the fungi (using the initial inoculation of 5 mg fresh weight/100 mL) in the BG11 medium without Synechocystis and without EM. The fresh weights of the fungi were dried to determine the dry weight.
