Effect of Low pH on Carbohydrate Production by a Marine Planktonic Diatom (Chaetoceros muelleri)

Table 1

Chaetoceros muelleri biomass and growth. Actual pH was the pH measured over the course of 6 days in culture. Growth rate derived from changes in in vivo chlorophyll fluorescence between days 2 and 5. Biomass is expressed as diatom concentration (cells mL⁻¹) and chlorophyll a (chl. a) concentration (𝜇g L⁻¹). These data were used to calculate chl. a content per cell (fg cell⁻¹) on day 5. Values are means ± standard deviation (𝑛=6 replicate cultures).

pH	Actual pH	Growth rate (𝜇′)	Doubling time (days)	Cells mL^−1	chl. a (𝜇g L^−1)	chl. a (fg cell^−1)
6.8	6.82±0.04	0.19±0.01	1.55±0.05	1.36×10^6±6.89×10^4	518 ± 89	378 ± 50
7.4	7.42±0.04	0.24±0.02	1.27±0.10	1.83×10^6±9.26×10^4	687 ± 141	375 ± 76
7.9	7.93±0.04	0.25±0.01	1.22±0.03	1.84×10^6±8.84×10^4	644 ± 80	351 ± 45
8.2	8.23±0.05	0.25±0.01	1.20±0.07	1.65×10^6±8.08×10^4	637 ± 68	388 ± 55