Effect of temperature on the composition of fatty acids in total lipids and phospholipids of entomopathogenic nematodes

Abstract

1. 1. Gas liquid chromatography was used to determine the composition of fatty acids in total lipids and phospholipids of the entomopathogenic nematodes, Steinernema feltiae Umeå strain, S. carpocapsae All strain, S. riobravis TX strain and S. feltiae NF strain that had been recycled or stored at 5, 10, 15, 20 and 25°C. 2. 2. In all nematode strains, the unsaturation indices of total lipids increased as recycling or storage temperatures decreased. The unsaturation indices increased in the phospholipids of all strains except the TX strain of S. riobravis. 3. 3. Increased unsaturation indices at low temperatures was due to an increase in polyunsaturated fatty acids with concomitant decline in the proportion of saturated fatty acids, especially palmitic (16:0) and/or stearic (18:0) acids 4. 4. Steinernema riobravis displayed a lower degree of physiological adaptation to cold temperatures than the other strains. The saturated fatty acids and unsaturation index of this nematode's phospholipid did not change in response to recycling or storage temperatures.