Levans. V. Kinetics of the acid hydrolysis of <i>Streptococcus salivarius</i> levan

Abstract

Abstract The kinetics of the acid hydrolysis of Streptococcus salivarius levan were studied by examining the weight‐average molecular weight. The molecular weights were obtained in a continuous manner from light scattering. Two first order reactions were observed: an initial rapid reaction in competition with a slower reaction. Activation energies, activation entropies, as well as the rate dependence upon substrate and hydrogen ion concentrations were determined. The data seem to indicate that the fast reaction is related to the breaking of branch‐point bonds while the slower reaction is related to the breaking of main‐chain bonds. Thus, levan hydrolysis seems to be fundamentally different from the completely random degradation of other branched polysaccharides, i.e., dextran, glycogen, and amylopectin.