Effect of starvation on the distribution of positional isomers and enantiomers of triacylglycerol in the diatom Phaeodactylum tricornutum
2012
Abstract
The diatom Phaeodactylum tricornutum was cultivated in a standard medium and under sulfur, silicon, nitrogen and phosphorus starvation and its triacylglycerols (TAGS) were analyzed by RP-HPLC/MS-APCI. Nearly 100 molecular species of polyunsaturated TAGS were identified.
RP-HPLC was used to isolate positional isomers of TAGs, which were further separated by chiral HPLC. First eluted were those TAGs that have an eicosapentaenoic acid moiety in the sn-1 position.
The ratios of symmetrical to asymmetrical TAGs in P. tricornutum were affected under sulfur-, nitrogen-, phosphorus- and silica-starvation, i.e. in cultivations involving cells in nutrient stress. The ratios of positional TAGs and also the proportions of enantiomers were changed