关键词: 虾青素, 雨生红球藻, 光照强度, 光周期

Abstract: 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.

Key words: astaxanthin, Haematococcus pluvialis, light intensity, photoperiod