Main content area

Applying the strategy of light environment control to improve the biomass and polysaccharide production of Nostoc flagelliforme

Han, Pei-pei, Shen, Shi-gang, Wang, Hui-Yan, Yao, Shun-yu, Tan, Zhi-lei, Zhong, Cheng, Jia, Shi-ru
Journal of applied phycology 2017 v.29 no.1 pp. 55-65
Nostoc flagelliforme, biomass, biotechnology, cell growth, light intensity, lighting, microalgae, nitrogen, polysaccharides, urea, wavelengths, white light
The strategy of light environment control was applied to improve biomass and extracellular polysaccharides (EPS) production of the cyanobacterium Nostoc flagelliforme by adjusting multiple wavelengths (red 660 nm, blue 460 nm, green 520 nm) and light intensity assisted by nitrogen source optimization. A mixed wavelength with low light intensity was more suitable for cell growth. Wavelength shift approach, i.e., manipulation of light wavelength at appropriate culture stages, increased both biomass and EPS production, and optimum shift time was at 9 days. The effects of four nitrogen sources under different light conditions were subsequently evaluated, and urea showed the best performance. The optimized wavelength shift approach (9-day illumination with white light followed by 9-day culture with mixed wavelengths of red/blue/green = 12:5:5) with urea as nitrogen source improved the biomass from 0.72 ± 0.02 to 1.20 ± 0.02 g L⁻¹ (i.e., by 66 %) and EPS production from 27.31 ± 1.00 to 86.65 ± 2.56 mg L⁻¹ (i.e., by 217.3 %). These results provide information on novel culture strategies for microalgal biotechnology by applying light environment control.