摘要:
An immobilized enzyme is prepared for use in organic mediums essentially devoid of free water. An enzyme-containing liquid medium is contacted with a particulate porous carrier which preferably has a particle size of 200-1000 &mgr;m and a surface area of 20-1000 m2/g to adsorb the enzyme on the carrier, and volatile components of the liquid medium contained by the carrier are removed. The carrier may have a hydrophilic surface, and an amount of liquid medium is used to prevent agglomeration of the carrier. Alternatively, the carrier has a hydrophobic surface, and the addition of a hygroscopic substance suppresses agglomeration of the carrier by absorbing excess liquid. The hygroscopic substance may be removed during the removal of volatile components. Contacting of the enzyme-containing liquid and carrier can be in a fluidized bed where immobilization and removing volatile components are conducted simultaneously, or contacting can be in mixer followed by removing volatile components in a fluidized bed. The enzyme-containing liquid may be atomized onto the carrier in the fluidized bed or in the mixer. Enzymes immobilized include lipase, and the immobilized lipase can be used in trans-esterification reactions.
摘要:
A hyaluronic acid derivative, and methods of producing and using said derivative, the derivative comprising n repeating units and having the general structural formula (I), wherein, in at least one repeating unit, one or more of R1, R2, R3, R4 comprises an etherbound aryl/alkyl sulfone having the general structural formula (II), wherein R comprises an alkyl- or aryl-group, and otherwise R1, R2, R3, R4 are hydroxyl groups, OH.