Effect of γ-irradiation on membrane fatty acids and peptidoglycan's muropeptides of Pantoea agglomerans, a plant pathogen

Aims:  The aim of this study was to evaluate the effect of γ-irradiation on the fatty acids (FA) and muropeptides content of two strains of an Enterobacteriacea : Pantoea agglomerans .
Methods and Results:  Pantoea agglomerans strains ATCC 49174 and RL1 isolated from irradiated carrots were used for this study. Radiation treatments (1 and 3·5 kGy) were performed to study the radiotolerance. Total lipids were obtained by multiple extractions using methanol/chloroform (2 : 1) and were quantified by GC. Muropeptides were purified by successive enzymatic digestions and analysed using a reverse phase C₁₈ column in high performance liquid chromatography. A significant ( P  ≤ 0·05) modification of the bacterial wall was noticed for the membrane FA composition and the muropeptides.
Conclusion:  Effects of irradiation on the bacterial membrane are noticeable and could play an important role on the cellular response and ability to survive this harsh environment.
Significance and Impact of the Study:  To our knowledge, it is the first study to demonstrate the effects of ionizing irradiation on the modification of the FA and one of the few to confirm its effects on the muropeptides of the peptidoglycan.