Investigation the effect of molasses residue on the growth and astaxanthin accumulation of Haematococcus pluvialis

Abstract

    Haematococcus pluvialis is the richest natural source of astaxanthin available. Changes in nutritional and environmental factors stimulate algae to produce astaxanthin. Currently, there have been many studies investigate the nutritional factors affecting astaxanthin accumulation of Haematococcus algae . However, the application of nitrogen and green carbon sources to the culture of Haematococcus algae is limited in Vietnam. Therefore, this study used condensed molasses residue (condensed molasses solubles - CMS) as a medium to provide green nutrients for algae cultivation. Experimental results showed that CMS affects the growth and astaxanthin accumulation capacity of the algae H. pluvialis. When gradually increasing the CMS concentration from 0.01 % to 0.2 %, the biomass tended to increase gradually from 150.497 mg/L to 192.689 mg/L. The highest cell density was obtained in the CMS medium 0.2 % 19.3⨯10⁴ cell/mL with a specific growth rate of 0.05 mg/L per day. The highest cumulative astaxanthin concentration was found up to 3.1 % (compared to dry biomass) at low concentration of 0.01 % CMS. It indicated that the lower the CMS concentration, the faster the astaxanthin accumulation time.