Fatty acid and phospholipid composition of five psychrotrophic Pseudomonas spp. grown at different temperatures.

The free fatty acid and phospholipid composition of 5 psychrotrophic marine Pseudomonas spp. have been determined in chemostat culture with glucose as the limiting substrate over the range 0--20 degrees C. The predominant fatty acid present in all the isolates was hexadecenoic acid (C 16:1) together with lesser quantities of octadecenoic acid (C 18:1) whilst none contained acids with chain lengths exceeding 18 carbon atoms. Decreasing the growth temperature from 20 degrees C to 0 degrees C resulted in little significant change in fatty acid composition. The principal phospholipid components of the five psychrotrophic pseudomonads have been identified as phosphatidylserine, phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Decreasing the growth temperature did not elicit significant changes either in the total quantities of phospholipid synthesized or in the concentration of individual phospholipid components in any of the isolates. All the psychrotrophs showed maximum glucose uptake between 15 degrees C and 20 degrees C and the rate decreased rapidly as the temperature was decreased towards 0 degrees C.