Effect of light quality on the cultivation of chlorella pyrenoidosa

¹ School of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China
² School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China

^* Corresponding author: zhgfang77@zjgsu.edu.cn

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.