ACCUMULATION OF OLEIC ACID IN HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE) UNDER NITROGEN STARVATION OR HIGH LIGHT IS CORRELATED WITH THAT OF ASTAXANTHIN ESTERS¹

Abstract

The chlorophyte Haematococcus pluvialis accumulates large quantities of astaxanthin under stress conditions. Under either nitrogen starvation or high light, the production of each picogram of astaxanthin was accompanied by that of 5 or 3–4 pg of fatty acids, respectively. In both cases, the newly formed fatty acids, consisting mostly of oleic (up to 34% of fatty acids in comparison with 13% in the control), palmitic, and linoleic acids, were deposited mostly in triacylglycerols. Furthermore, the enhanced accumulation of oleic acid was linearily correlated with that of astaxanthin. Astaxanthin, which is mostly monoesterified, is deposited in globules made of triacylglycerols. We suggest that the production of oleic acid‐rich triacylglycerols on the one hand and the esterification of astaxanthin on the other hand enable the oil globules to maintain the high content of astaxanthin esters.

The effects of abscisic acid, salicylic acid and jasmonic acid on lipid accumulation in two freshwater <i>Chlorella</i> strains

“…One of the lipids is carotenoid (e.g. b-carotene, lutein or astaxanthin), which serves as a "sunscreen" to prevent or reduce excess light from irradiating the chloroplast under stress (Zhekisheva et al, 2002). Moreover, lipid synthesis may also utilize phosphatidylcholine, phosphatidyl ethanolamine and galactolipids or toxic fatty acids excluded from the membrane system as acyl donors, thereby serving as a mechanism to detoxify membrane lipids and deposit them in the form of triacylglycerols (Breuer et al, 2013;Hu et al, 2008).…”

Effects of Environmental Factors and Nutrient Availability on the Biochemical Composition of Algae for Biofuels Production: A Review

“…and Haematococcus pluvialis are observed to accumulate high amounts of carotenoids, astaxanthin and its acylesters (up to 13% w/w), when grown under nitrogen-depleting conditions [173][174][175]. Zhekisheva et al [176] reported that under nitrogen depleting conditions, Haematococcus pluvialis produced fatty acids and astaxanthin in a 5:1 ratio. It was suggested that the production of the oleic acid-rich triacyl-glycerols and the esterification of the astaxanthin, maintain a high content of astaxanthin esters by enabling the oil globules.…”

Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances

“…The formation of a C18 fatty acid consumes approximately 24 NADPH derived from the electron transport chain, which is twice that required for synthesis of a carbohydrate or protein molecule of the same mass, and thus relaxes the overreduced electron transport chain under high light or other stress conditions. The TAG synthesis pathway is usually coordinated with secondary carotenoid synthesis in algae (Rabbani et al, 1998;Zhekisheva et al, 2002). The molecules (e.g.…”