Effects of external rare earth La3+ on growth and physiological property of arthrospira in alkaline lake of erdos plateau

The effects of La3+ on the growth of Arthrospira platensis in the alkaline lake of Erdos Plateau (S1) were studied by the physiological and biochemical method. The results showed that a certain amount of lanthanum played a catalytic role on the growth of S1. The effect of lanthanum on the algae cells in the early growth stage was not obvious, but increased significantly with time (p<0.05). The growth of S1 was much quicker when the concentration of lanthanum was between 38.53 and 53.94 μmol·L-1. The growth and the content of chlorophyll a, intracellular polysaccharide, soluble protein of S1 were most significant as the concentration of lanthanum was 53.935 μmol·L-1 (p<0.01). The growth of algae cell was inhibited when the concentration of lanthanum was over 53.94 μmol·L-1.