Effect of growth temperature on the positional distribution of eicosapentaenoic acid and trans hexadecenoic acid in the phospholipids of a Vibrio species of bacterium.
Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were isolated from a Vibrio species of bacterium, known to produce eicosapentaenoic acid (20:5n-3) and trans-hexadecenoic acid (16:1n-7), and subjected to phospholipase A2 degradation to determine the positional distribution of component fatty acids. At the two growth temperatures studied (20 and 5 degrees C), both 20:5n-3 and trans 16:1 n-7 were located mainly at position sn-2 in PE. Increases in the proportions of 20:5n-3 and trans 16:1n-7 in position sn-2 with decreasing growth temperature were balanced mainly by decreases in the level of iso-15:0. In PG, trans 16:1n-7 was located predominantly in position sn-1, although the difference between the two positions was not as great as in PE. Eicosapentaenoic acid was preferentially located in position sn-2 of PG, particularly at 5 degrees C when it comprised 29.9% of the total fatty acids in this position. It is concluded that trans 16:1n-7/20:5n-3 is not a major molecular species of phospholipid in this species of Vibrio and that changes in the levels of molecular species of PE containing iso-15:0 may feature in thermal acclimation.
Henderson
R J
RJ
Department of Biological and Molecular Sciences, University of Stirling, Scotland.
Millar
R M
RM
Sargent
J R
JR
D015118:Eicosapentaenoic Acid / Q000032:analysis*; D010169:Palmitic Acids / Q000032:analysis*; D010743:Phospholipids / Q000737:chemistry*; D013696:Temperature; D014733:Vibrio / Q000254:growth & development / Q000378:metabolism*
D010169:Palmitic Acids; D010743:Phospholipids; C093821:hexadecenoic acid; D015118:Eicosapentaenoic Acid