Combined resistance to oxidative stress and reduced antenna size enhance light-to-biomass conversion efficiency in Chlorella vulgaris cultures

Table 3 Growth parameters of WT, PG-14 and SOR strains, cultured in air/CO₂ bubbling system

Genotype	Lab-scale, indoor PBR
	1400 µmol photons m⁻² s⁻¹		50 µmol photons m⁻² s⁻¹
	Mean increase of biomass (g l⁻¹ day⁻¹)	μ (day⁻¹)	Mean increase of biomass (g l⁻¹ day-1)	μ (day⁻¹)
WT	0.43 ± 0.03^a	1.87 ± 0.08^a	0.059 ± 0.023^a	0.94 ± 0.09^a
PG-14	0.55 ± 0.02^b	2.00 ± 0.07^b	0.024 ± 0.004^b	0.85 ± 0.13^a
SOR-1	0.58 ± 0.03^b	1.97 ± 0.04^a,b	0.059 ± 0.008a	0.94 ± 0.08^a
SOR-5	0.70 ± 0.03c	2.07 ± 0.03c	0.048 ± 0.002c	0.94 ± 0.09^a
SOR-6	0.72 ± 0.04c	2.09 ± 0.03c	0.049 ± 0.015c	0.94 ± 0.08^a

Biomass increase was measured by the determination of dry biomass accumulated after the cultivation period, divided by the number of days of cultivation (see Fig. 6). µ, specific growth rate, was calculated from the slope of logarithmic cell concentration curve. Growth was performed under autotrophic conditions, in 1-L cylinders, illuminated with either 1400 or 50 µmol photons m⁻² s⁻¹, 25 °C. Data are expressed as mean ± SD, n > 3. For each parameter and condition measured, significant different values among genotypes (ANOVA test, p < 0.05) are marked with different letters