雨生红球藻的光周期效应

Effect of Photoperiod on Microalgae Haematococcus pluvialis

雨生红球藻(Haematococcus pluvialis)是一种单细胞淡水绿藻,是自然界已知的中虾青素含量最高的生物物种。通过分析3种光照强度(70、120和300μmol·m–2·s–1)下雨生红球藻细胞形态、生长速率和虾青素含量的差异,对其光周期效应进行了研究。结果表明,不同光强下适宜雨生红球藻生长的光周期均为16小时光照/8小时黑暗,光强为120μmol·m–2·s–1时其细胞生长速率最大,为0.43d–1;细胞内虾青素含量随着光强和光照时间的增加而增加,在300μmol·m–2·s–1光强下连续光照15天后,藻细胞呈亮红色,平均直径为21.02μm,最大虾青素值达39.40pg·cell–1。

Haematococcus pluvialis is a green microalga with the largest astaxanthin content among all the potential organism sources in the world. Astaxanthin is a red ketocarotenoid with high antioxidant ability and has been widely used in aquaculture, nutraceutical, cosmetic and food industries. Illumination is an essential factor for the photosynthesis of algae. As well, light intensity and photoperiod greatly affect the growth and astaxanthin accumulation of H. pluvialis. In this work, we studied the effect of photoperiod on the growth and astaxanthin accumulation of H. pluvialis under different light intensities （70, 120 and 300 μmol·m–2 ·s–1） by analyzing cell morphologic features, growth rate and astaxanthin content under different conditions. The suitable photoperiod was 16/8 h, with maximal growth 0.43 d–1 obtained at 120 μmol·m–2 ·s–1 . The astaxanthin content within a single cell increased with the light intensity and illumination time increases. After 15 days, the alga cell turned bright red under continuous illumination at 300 μmol·m–2 ·s–1 , with average diameter 21.02 μm. The highest astaxanthin content was 39.40 pg·cell–1 .