Abstract
Effect of light quality, including red light, blue light, white light, red and blue mixing light with 8:1, 8:2 and 8:3, on the growth characteristics and metabolite accumulation of chlorella pyrenoidosa was conducted based on light emitting diode (LED). Results showed that chlorella pyrenoidosa grew best under blue light, and the optical density, specific growth rate and biomass of chlorella pyrenoidosa was about 2.4, 0.10 d-1 and 6.4 g·L-1, respectively, while the optical density of chlorella pyrenoidosa was between 1.0 and 1.7, specific growth rate was between 0.06-0.10 d-1 and biomass was between 2.7 and 3.8 g·L-1 under other light quality after 30 days of cultivation. The optical density, specific growth rate and biomass of chlorella pyrenoidosa was approximately 2.05 times, 1.33 times and 2.06 times under blue light than red light, respectively. Moreover, Red and blue mixing light was conducive to the synthesis of chlorophyll a and carotenoids of chlorella pyrenoidosa, and blue light could promote the synthesis of chlorophyll b. Chlorophyll a and carotenoids content of chlorella pyrenoidosa was 13.5 mg·g-1and 5.8 mg·g-1 respectively under red and blue mixing light with 8:1, while it was 8.4 mg·g-1 and 3.6 mg·g-1 respectively under blue light. Red and blue mixing light was more conducive to protein and total lipid content per dry cell of chlorella pyrenoidosa. Protein and total lipid content was 489.3 mg·g-1 and 311.2 mg·g-1 under red and blue mixing light with 8:3, while it was 400.9 mg·g-1 and 231.9 mg·g-1 respectively under blue light.
Highlights
Light is one of the most important environmental factors in the growth and biochemical composition of microalgae cell, and it has significant impact on microalgae’s growth, photosynthesis, algae color, cell morphogenesis and metabolites accumulation [1, 2]
Algal cells are in the lag phase and the growth rate is slow, and no significant difference in algal cell growth was found among different light quality on the first 15 days after inoculation
Our results showed that red and blue mixing light was conducive to the synthesis of chlorophyll a and carotene of chlorella pyrenoidosa, and blue light could accelerate the synthesis of chlorophyll b
Summary
Light is one of the most important environmental factors in the growth and biochemical composition of microalgae cell, and it has significant impact on microalgae’s growth, photosynthesis, algae color, cell morphogenesis and metabolites accumulation [1, 2]. The variation of illumination in nature has regularity and stability, and microalgae form the specific reaction to light in the long evolutionary. It is one of the important ways to improve microalgae’s yield and quality to apply appropriate light technology on microalgae cultivation to accelerate its growth reproduction and to adjust its nutrient composition [3,4,5]. It is easy to realize the adjustment of light intensity and light photoperiod, and studies of light environments on microalgae growth have stressed on light intensity and light photoperiod recently. Few study was carried out to focus on light quality on the growth and metabolism of microalgae
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
