Table II. Photosynthetic rate in log and stationary phases.

Photosynthetic rate (µmol oxygen L⁻¹ s⁻¹ cell⁻¹) determined on the 4th day of culture (log phase) and 3 d after the onset of the stationary phase at 50 µmol photons m⁻² s⁻¹ (ML) and 200 µmol photons m⁻² s⁻¹ (HL), with or without the addition of CO₂. Statistics are as described for Table I.

Culture	Log		Stationary
	ML	HL	ML	HL
Nitrate	6.06 × 10−10 ± 2.50 × 10−11 def	5.44 × 10−10 ± 8.00 × 10−11 cde	2.28 × 10−10 ± 3.74 × 10−11 a	5.82 × 10−10 ± 6.33 × 10−11 b
Ammonium	4.61 × 10−10 ± 6.18 × 10−11 abcd	7.23 × 10−10 ± 4.69 × 10−11 f	2.75 × 10−10 ± 2.41 × 10−11 a	5.55 × 10−10 ± 5.23 × 10−11 b
Urea	3.89 × 10−10 ± 2.92 × 10−11 ab	6.20 × 10−10 ± 7.56 × 10−11 ef	2.23 × 10−10 ± 9.63 × 10−12 a	3.70 × 10−10 ± 1.11 × 10−10 a
Nitrate + CO2	5.29 × 10−10 ± 2.92 × 10−11 bcde	5.72 × 10−10 ± 7.41 × 10−11 def	3.15 × 10−10 ± 7.82 × 10−12 a	6.09 × 10−10 ± 1.10 × 10−11 b
Ammonium + CO2	4.01 × 10−10 ± 2.47 × 10−11 abc	3.18 × 10−10 ± 3.64 × 10−11 a	2.59 × 10−10 ± 1.36 × 10−11 a	3.02 × 10−10 ± 6.66 × 10−11 a