Lipid accumulation in response to nitrogen limitation and variation of temperature in Nannochloropsis salina

Botanical Studies

Table 1 Growth measurements and lipid productivity of Nannochloropsis salina operated at different nitrogen concentrations and temperatures

	Cell count	Optical density	Dry weight of cells	Lipid productivity
	(×10⁶/ml)	(OD₆₈₀)	(g L⁻¹)	(g L⁻¹ day⁻¹)
Control	9.93 ± 0.25	0.77 ± 0.04	0.61 ± 0.03	0.23 ± 0.0
75	9.07 ± 0.45^a*	0.71 ± 0.03^a*	0.57 ± 0.06	0.24 ± 0.0^a*
50	8.23 ± 0.45^ab	0.65 ± 0.02^ab	0.53 ± 0.05^a*	0.30 ± 0.0^ab
25	7.86 ± 0.45^ab	0.63 ± 0.02^ab	0.48 ± 0.02^ab	0.37 ± 0.0^abc*
Temperature°C
15	6.87 ± 0.55	0.53 ± 0.03	0.42 ± 0.05	0.31 ± 0.0
20	7.57 ± 0.35^a	0.59 ± 0.02^a	0.45 ± 0.04	0.35 ± 0.01^a
25	8.23 ± 0.25^ab	0.66 ± 0.01^ab	0.50 ± 0.04^a	0.37 ± 0.01^ab
30	8.67 ± 0.06^ab	0.71 ± 0.03^abc	0.53 ± 0.02^ab	0.43 ± 0.0^abc
35	8.57 ± 0.25^ab	0.72 ± 0.02^abc	0.51 ± 0.02^a	0.41 ± 0.01^abcd

Mean ± SE (n = 3) followed by different letters indicate significant difference at P ≤ 0.05, according to one-way analysis of variance (ANOVA) and the LSD (least significant difference) test (a*: significant with control at ≤0.05, b*: significant with 75% N at ≤0.05, c*: significant with 50% N at ≤0.05, a: significant with 15°C at ≤0.05, b: significant with 20°C at ≤0.05, c: significant with 25°C at ≤0.05, d: significant with 30°C at ≤0.05).