Desiccation-induced damage to the cell envelope of root-nodule bacteria

Leakage of materials reacting with the fluorescent probe 1-anilino-8-naphthalcne sulphonate (ANS) from root-nodule bacteria subjected to desiccation and rehydration suggests that death of these bacteria is associated with changes in membrane permeability. The slow-growing rhizobia and the fast-growing Rhizobium meliloti differ from other fast-growing bacteria of the R. leguminosarum group in that they exhibit little fluorescence in the presence of ANS. This probably reflects differences between these groups of bacteria in the polar/non-polar nature of the outer cell envelopes. Following desiccation and rehydration, all groups of root-nodule bacteria fluoresced strongly in the presence of ANS.Repair of desiccation-induced damage to the cell envelopes of R. japonicum QA372. R. trifolii SU297/32B and R. meliloti CC131 was not observed using a range of screening agents. However, repair of significant numbers of lysozyme-sensitive bacteria was observed with R. leguminosarum TA101 within an hour of rehydration.