THE CHARACTERISTICS OF GROWTH AND NUTRIENT CONSUMPTION OF HAEMATOCOCCUS PLUVIALIS UNDER RED LIGHT

It has been proposed that Haematococcus pluvialis grow better under red light than PAR. In the present study, the characteristics of chlorophyll fluorescence parameters and nutrient requirements during population growth under red light were analyzed. The results showed that chlorophyll fluorescence parameters PS II, qP and ETR had the same variation trend along with the population growth phase. Fv/Fm and NPQ decreased with the increased cell numbers, and then increased at the late growth stage when the cell density decreased. The turning point of Fv/Fm and NPQ is practically consistent with the cell stress condition caused by nutrient depletion stress. High concentrations of the nutrients nitrogen (N) and phosphorus (P) such as 85/8.5 mg/L and 130/13.0 mg/L enhanced the biomas at early stage, and then inhibited cell growth at the longer retarded phase before entering exponential growth phase that Nutrient consumption was also reduced. These results suggested that the optimum of N/P concentration for H. pluvialis cultured under red light was 45/4.5 mg/L. The potential application of the results in semi-continuous culture of H. pluvialis has been discussed.