A RESPONSE SURFACE APPROACH FOR THE PRODUCTION OF NATURAL PIGMENT ASTAXANTHIN FROM GREEN ALGA, HAEMATOCOCCUS PLUVIALIS: EFFECT OF SODIUM ACETATE, CULTURE AGE, AND SODIUM CHLORIDE

Abstract

ABSTRACT The effect of sodium acetate, sodium chloride and Haematococcus pluvialis culture age on biomass yield, astaxanthin content and astaxanthin production was investigated using response surface methodology in a batch mode of cultivation. An orthogonal experimental design, with three variables (at five coded levels of −1.682, −1, 0, 1 and 1.682) and three response functions, was employed to study the effect of the individual variable on the response functions. The response functions correlated well (r≥0.98, p≤0.01) with these variables by second order polynomials consisting of linear, quadratic and interaction terms. The effect of culture age dominated over the sodium acetate and sodium chloride concentrations. Optimum conditions for achieving high astaxanthin content (>1.4%w/w) and astaxanthin production (13 mg/L) were found to be with 31–50 mM sodium acetate and 0.55–0.63% (w/v) of sodium chloride.