1.Marine Biology Institute of Shandong Province， Qingdao 266104， China； 2.Qingdao Macroalgae Engineering Technology Research Center， Qingdao 266104， China； 3.College of Life Science， Yantai University， Yantai 264005， China
Abstract: The effects of cadmium concentrations on growth，physiological biochemical characteristics including photosynthetic pigment， soluble sugar and soluble protein)and bioactive accumulation of fucoxanthin， alginate and phlorotannins were studied in brown alga Sargassum horneri exposed to cadmium concentrations of 0，0.1，0.5，1.0 and 5.0 mg/L prepared by CdCl2·2.5 H2O at water temperature of 15℃ for 15 days to evaluate effects of heavy metal polution on growth and quality of economically important sea weed.The results showed that the brown alga in control group had continual increase in specific growth rate(SGR)in thalli.The brown alga exposed to 0.1 and 0.5 mg/L Cd， however， showed gradual increase in SGR during the first 10 days and then stable to 15thday， the brown alga exposed to 1.0 mg/L Cd showing a fluctuation trend in SGR with time，and exposed to 5.0 mg/L having elevated SGR first and then being decreased.The physiological biochemical indices of the macroalgae were found to be varied with exposed period， on the 15thday， significantly lower contents of chlorophyll a， carotenoid and soluble protein than those in the control group(p＜0.05)， and significantly higher soluble sugar content than that in the control group(p＜0.05).The contents of fucoxanthin and phlorotannins were found to be decreased significantly in the brown alga under Cd stress，with the greater decline range at higher concentration of Cd.There was no significant change in alginate content under Cd concentration of≤0.5 mg/L(P＞0.05)， significant decrease at Cd concentration of≥1.0 mg/L(p＜0.05).The findings suggest that the heavy metal pollution be considered as an important factor in development of the brown alga industry in mariculture area.
2017, Vol. 32 
