Abstract:We studied the effects of temperature and light intensity on growth, photosynthetic pigment content, and nutrient components in Sargassum horneri. These factors had significant effects (P<0.05) on all three aspects. S. horneri survived at 5℃~20℃ and 50~300 μmol/(m2·s) The optimal conditions, at which specific growth rate was the highest, were 20℃ and 200~300 μmol/(m2·s). At temperatures above 25℃, the blades stopped growing, became pale, and rotted. S.horneri accumulated the most photosynthetic pigment at 25℃ and 50 μmol/(m2·s). The effects of light intensity were not significant. Soluble sugar content and soluble protein content were the highest at 10℃~20℃, and ash and crude protein content were the highest at 5℃~10℃ and 50 μmol/(m2·s). Ether extract yield was low at 10℃ and 25℃, peaked between these values, and did not vary significantly with light intensity. Alginate content was the highest at 10℃ and 100 μmol/(m2·s), and fucoxanthin content was the highest at 10℃ and 50 μmol/(m2·s). Phlorotannin content increased with increasing light intensity from 200 to 300 μmol/(m·s), where it reached a maximum; it reached local maxima at 5℃ and 25℃, and was lower between these values. S. horneri grew faster atc. 20℃ and 200~300 μmol/(m2·s), whereas color and vigor were better at 10℃ and 100 μmol/(m2·s). Its long body length and fast growth make it ideal for large-scale culturing. The nutrient components varied with culture conditions. S. horneri is a health food of moderate protein and low fat content, with high levels of functional components such as alginate, fucoxanthin, and polyphenols. It can therefore be used to provide raw material for food additives and to obtain its active components. These findings provide reference values for culturing S. horneri and extracting its components.
