Low temperature thermal behaviour of lipopolysaccharides from Brucella and other Gram-negative bacteria

Abstract In lipopolysaccharides (LPSs) from Brucella and other Gram-negative bacteria, cooling to temperatures between −13 and −36°C gives rise to a phase transition between different ordered supramolecular arrangements. During a subsequent heating program in DSC, the thermal effect temperatures that show the phase transition for each LPS are in inverse relationship with their respective thermolysis temperatures. Both effects, thermolysis and cooling phase transition, have been related to the relative strength of the linkage types in the O -change structure and to the facilities for intermolecular hydrogen bonding.