Effects of overexpression of a bHLH transcription factor on biomass and lipid production in Nannochloropsis salina

Table 2 Specific growth rate, biomass productivity, and FAME content of WT and two NsbHLH2 transformants

Culture condition	Strain	Specific growth rate (day⁻¹)^a			Biomass productivity (mg/L/day)		FAME content (%)
		Day 0–4^b	Day 4–8^c	Day 8–12^d	8 day	12 day	8 day	12 day
Normal	WT	0.43 ± 0.04	0.47 ± 0.03	0.15 ± 0.01	89.6 ± 8.8	168.8 ± 10.4	15.6 ± 0.8	21.7 ± 0.9
	3–6	0.59 ± 0.03**	0.35 ± 0.04	0.11 ± 0.02	121.9 ± 11.5*	176.0 ± 9.7	16.5 ± 0.7	24.5 ± 1.2
	3–11	0.67 ± 0.03**	0.32 ± 0.03	0.10 ± 0.03	133.3 ± 23.0	170.8 ± 9.9	16.5 ± 1.1	24.1 ± 1.6
N limitation	WT	0.40 ± 0.04	0.36 ± 0.36		78.1 ± 2.4		42.3 ± 1.4
	3–6	0.64 ± 0.02**	0.12 ± 0.01		96.3 ± 5.4*		46.0 ± 3.3
	3–11	0.60 ± 0.03**	0.14 ± 0.02		93.7 ± 6.3*		41.5 ± 1.2
Osmotic stress	WT	0.38 ± 0.04	0.48 ± 0.03	0.21 ± 0.04	102.1 ± 12.3	168.7 ± 12.1	17.2 ± 0.9	30.1 ± 3.0
	3–6	0.46 ± 0.04	0.47 ± 0.05	0.11 ± 0.02	126.0 ± 15.9	180.1 ± 4.9	17.8 ± 1.2	32.5 ± 3.8
	3–11	0.46 ± 0.02	0.38 ± 0.01	0.14 ± 0.02	131.2 ± 19.6	153.1 ± 4.6	17.2 ± 0.4	29.9 ± 4.7

The data points represent the average of samples and error bars indicate standard error (n = 4). Significant differences, as determined by Student’s t test, are indicated by asterisks (* P < 0.05, ** P < 0.01, *** P < 0.001)
^aSpecific growth rate was calculated as (μ/day) = ln(X ₂/X ₁)/(t ₂ − t ₁); where X ₁ and X ₂ are the initial and final biomass and t ₁ and t ₂ are the initial and final times
^bSpecific growth rate based on cell density on day 0 and day 4
^cSpecific growth rate based on cell density on day 4 and day 8
^dSpecific growth rate based on cell density on day 8 and day 12

ISSN: 2731-3654