Profiling of carotenoids in six microalgae (Eustigmatophyceae) and assessment of their β-carotene productions in bubble column photobioreactor

Abstract

The profiles of carotenoids and production of β-carotene by six eustigmatophytes, Eustigmatos magnus, Eustigmatos polyphem, Eustigmatos vischeri, Vischeria helvetica, Vischeria punctata and Vischeria stellata, grown in a bubble column photobioreactor were measured. All eustigmatophytes contained β-carotene, violaxanthin and vaucheriaxanthin as their major carotenoids and accumulated large amount of β-carotene, which accounted for over 50 % of total carotenoids. Maximum intracellular β-carotene contents ranged 1.5-3.5 % of dry wt and in V. stellata it reached 5.9 % dry wt, accompanied by a biomass dry wt >7.3 g/l, with the highest up to 9.8 g/l. These eustigmatophytes are thus promising producers of β-carotene.

Current bioeconomical interest in stramenopilic Eustigmatophyceae: a review

“…The rich palette of carotenoid pigments in different genera of Eustigmatophyta [12] logically led to the recent studies of their commercial biotechnological potential. Six species of genus Vischeria were reported as possible novel sources of natural b-carotene due to their considerable production in bubble column and flat panel photobioreactors (100 and 470.2 mg L À1 , respectively) [22,23]. b-Carotene is best known for its provitamin A activity function and strong stimulatory effect on the immune system.…”

“…b-Carotene is best known for its provitamin A activity function and strong stimulatory effect on the immune system. It is now of increasing demand and has extensive applications [22,23]. As AsX, it is broadly used as a colorant and feed additive (E160a [24]), antioxidant, heart-preventive and anticancer agent in the food and aquaculture, pharmaceutical and cosmetics industries [25].…”

“…Presently, the primary algal source of b-carotene is the green microalga Dunaliella salina. However, researchers have yet to achieve high b-carotene concentration in the total low biomass yield (1.5-2 g L À1 ) under harsh conditions of high salinity, high light intensity (>500 mmol photons m À2 s À1 ) and low temperature [22]. To date, the b-carotene content in the studied Vischeria strains is lower than that in Dunaliella (up to 7% of the dry weight vs. 10%, respectively), although Li et al [22] believed that it could be increased with improvement of the culture conditions.…”

“…However, researchers have yet to achieve high b-carotene concentration in the total low biomass yield (1.5-2 g L À1 ) under harsh conditions of high salinity, high light intensity (>500 mmol photons m À2 s À1 ) and low temperature [22]. To date, the b-carotene content in the studied Vischeria strains is lower than that in Dunaliella (up to 7% of the dry weight vs. 10%, respectively), although Li et al [22] believed that it could be increased with improvement of the culture conditions. Further, some eustigmatophyceans (and particularly Vischeria stellata) accumulate higher biomass than Dunaliella and therefore, considering their high intracellular b-carotene content, may be more promising as future natural sources of this pigment.…”

Induction of carotenoid and phytosterol accumulation in microalgae

“…As light contributes greatly to β-carotene accumulation, the effect of red and blue light on the carotenoid biosynthesis process was studied recently and the results suggested that the combination of red and blue light along with long-term iterative stress led to higher β-carotene accumulation in D. salina (Fu et al, 2013). and were found to accumulate β-carotene at 1.5 -5.9% of its dry weight (Li et al, 2012a).…”