Measurement of native dextran synthesis and sedimentation properties by analytical ultracentrifugation

The principle of integrated enzymatic synthesis and product separation is e xamined with the aid of an analytical ultracentrifuge. The biosynthesis of high molecular weight dextran polymer from sucrose using dextransucrase enz yme was chosen as the test reaction. Tests on pre-synthesised native dextra n served to evaluate the process whilst allowing assessment of native dextr an sedimentation properties. Native dextrans were found to have fully corre cted sedimentation coefficients of 143-531 Svedbergs at infinite dilution. The biocatalytic formation of dextran was observed both visually and by mea surement of the build-up of sedimented material in the ultracentrifuge cell . Sedimentation coefficients comparable to those observed for pre-synthesis ed dextran were recorded. (C) 1999 Society of Chemical Industry.