Effects of cerium on cell growth and astaxanthin production of Haematococcus pluvialis

The effects of rare earth element cerium on the cell growth and astaxanthin production of Haematococcus pluvialis were studied.The results showed that lower concentration of Ce~(3+) could improve both the growth rate and astaxanthin production of the microalgae.When the Ce~(3+) of 0.1 mg/L concentration was added,the cell number of H.pluvialis was 34% more than the controls.1 mg/L concentration was the best to accumulate astaxanthin.The astaxanthin content under stress condition could be 3.2% of the cell dry mass,which was 167% higher than the controls.Additionally,higher concentration of Ce~(3+) restrained the growth and astaxanthin production of H.pluvialis.