Lipid composition, lipid fluidity and radioresistance of Deinococcus radiodurans and two mutant strains

Abstract The lipid composition of D. radiodurans strain R 1 and of two mutant strains has been studied in relation to membrane fluidity and sensitivity to X-ray radiation. No significant difference in the unsaturation degree of fatty acids was found between parental and mutant strains. An important decrease of carbohydrate-containing lipids was observed in the radiosensitive mutant strain. We also observed a higher fluidity in both mutant strains than in the parental one. Modification of membrane lipid fluidity by growing the parental strain at 39°C did not lead to modified radioresistance. These results suggest that a particular chemical composition of the membrane leading to a special lipid phase may be an important parameter in controlling radiosensitivity.