Influence of growth rate and sodium chloride concentration on the phospholipid composition of Pseudomonas fragi

The phospholipid composition of Pseudomonas fragi grown in glucose‐limited chemostat in the presence of 5 and 25 g sodium chloride l−1 was determined. Total phospholipid content decreased with increasing growth rate and was approximately 10% lower (at all growth rates) in the high‐salt cells than in the low‐salt cells. Phosphatidylglycerol and phosphatidylethanolamine content varied with growth rate but no major differences were detected between low‐salt and high‐salt cells. The results suggest that, unlike the case of halophilic micro‐organisms, an increase in the net negative charge by modification of phospholipid composition does not occur in P. fragi in response to increased external salinity.