ZHEKISHEVA, MIRASH*, SAMMY BOUSSIBA, INNA KHOZIN-GOLDBERG, ALIZA ZARKA, and ZVI COHEN. Microalgae Biotechnology Laboratory, The Jacob Blaustein Institute for Desert Studies, Ben-Gurion University of the Negev, Sede-Boker Campus, Israel, 84990. - Accumulation of triacylglycerols in Haematococcus pluvialis is correlated with that of astaxanthin esters.
The chlorophyte Haematococcus pluvialis accumulates large
quantities of astaxanthin under stress conditions. Under either
nitrogen starvation or high light, the proportion of each pg of
astaxanthin was accompanied by that of 5 or 3-4 pg of fatty acids,
respectively. In both cases, the newly formed fatty acids, consisted
mostly of oleic (up to 34% of fatty acids in comparison to 13% in the
control), palmitic and linoleic acids, were deposited mostly in
triacylglycerols. Furthermore, the enhanced production of oleic acid
was linearly correlated with that of astaxanthin. Astaxanthin which is
mostly monoesterified, is deposited in globules made of
triacylglycerols. We suggest that the production of tailor-made 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.
Key words: carotenoids, Haematococcus, high light, nitrogen starvation, oleic acid, triacylglycerols