Optimization of culture conditions for a newly isolated microalga Haematococcus pluvialis

Abstract:

The suitable culture conditions for the growth of a newly isolated microalga Haematococcus pluvialis were investigated. The light intensity, culture temperature and inoculation density for optimal growth of the microalga were obtained as 105 μmol/(m²·s), 21 ℃and 7.5×10⁴ cells/mL respectively based on cell density as the indicator via single factor test. The growth performance (cell density) of the microalga could be predicted with the quadratic polynomial equation established by response surface method (RSM) coupled with Box -Behnken design. Light intensity, culture temperature and inoculation density as well as their binomial had significant effects on the cell density of H. pluvialis in cultivation. The weight of influence from the factors was as follows: inoculation density > light intensity > culture temperature. The combined culture conditions for optimal growth of H. pluvialis predicted by RSM were light intensity 120 μmol/(m²·s), temperature 20 ℃ and inoculation density 9.25×10⁴ cells/mL.Confirmatory test showed a cell density of 45.08 ×10⁴ cells/mL in culture was obtained under the predicted optimal combined culture conditions, which was 6.9% higher than the highest cell density of the culture under optimal culture conditions based on single factor test.