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Table 1 C. vulgaris culture characteristics during nitrogen limited growth when supplemented with various bicarbonate salts

From: Optimized inorganic carbon regime for enhanced growth and lipid accumulation in Chlorella vulgaris

Treatment Cell concentration (×107 cells mL−1) Cell doublingsa Dry weight (g L−1; DCW)b Endpoint pH Total chlorophyll (mg L−1) Total chlorophyll per cell (pg) Dry weight per cell (ng)
0 mM HCO3 3.48 ± 0.17 2.47 ± 0.23 0.37 ± 0.03 8.08 ± 0.07 1.82 ± 0.08 0.052 ± 0.004 0.011 ± 0.001
50 mM ACS grade NaHCO3 2.15 ± 0.17* 1.35 ± 0.19* 0.58 ± 0.06** 9.82 ± 0.03** 2.00 ± 0.34 0.093 ± 0.011** 0.027 ± 0.001**
50 mM industrial grade NaHCO3 1.78 ± 0.13* 0.64 ± 0.40* 0.60 ± 0.02** 9.82 ± 0.06** 1.72 ± 0.18 0.097 ± 0.016** 0.034 ± 0.003**
50 mM KHCO3 1.56 ± 0.13* 0.88 ± 0.27* 0.54 ± 0.03** 9.77 ± 0.03** 2.01 ± 0.21 0.129 ± 0.013** 0.035 ± 0.003**
50 mM NH4HCO3 0.62 ± 0.04* −0.25 ± 0.47* 0.15 ± 0.04* 9.31 ± 0.05** 0.31 ± 0.17* 0.031 ± 0.014 0.016 ± 0.005
50 mM Na2CO3 1.21 ± 0.22* 0.83 ± 0.15* 0.35 ± 0.01 9.98 ± 0.02** 1.37 ± 0.15* 0.115 ± 0.024** 0.029 ± 0.006**
25 mM NaHCO3∙Na2CO3 1.21 ± 0.16* 0.38 ± 0.42* 0.49 ± 0.04** 9.83 ± 0.03** 1.77 ± 0.22 0.149 ± 0.036** 0.041 ± 0.008**
  1. Values are reported for the completion of the experiment (5.75 days) (n = 3)
  2. * p value <0.05 as determined by a two-tailed t test, statistically significantly lower [difference between treatment and control group (0 mM HCO3 )]
  3. ** p value <0.05 as determined by a two-tailed t test, statistically significantly higher [difference between treatment and control group (0 mM HCO3 )]
  4. aCell doublings are calculated as n = log2(Cf/Ci); where n is the number of cell doublings and C f and C i are final and initial cell concentrations, respectively
  5. bDry cell weight (DCW) determined gravimetrically with lyophilized biomass