Effect of o-acyl substituents on the functional behaviour of Rhizobium meliloti succinoglycan.

The effects of selective removal of acetyl or succinyl substituents on the functionality of succinoglycan polysaccharide have been studied by comparing the behaviour of the polysaccharides isolated from native Rhizobium meliloti strain Rm1021, and genetically modified R. meliloti species. Removal of the succinyl groups was found to dramatically improve pseudoplasticity of the aqueous succinoglycan samples and also increase the cooperativity of the order-disorder transition exhibited by the polysaccharide. Removal of the acetyl substituent led to a decrease in the order-disorder transition temperature, whereas the removal of the succinyl groups led to an increase.