Preparation and characterisation of gelatine hydrogels predisposed to use as matrices for effective immobilisation of biocatalysts
Physical, enzymatic and chemical methods were used to develop an efficient procedure for preparing gelatine hydrogels of appropriate strength and elastic properties for applications as enzyme carriers. The concentrations of the crosslinking enzyme (transglutaminase) the initial amount of gelatine, the production time and the effect of additional crosslinking with glutaraldehyde were examined. As a result, the following conditions were selected: 0.1 g cm 3 solution of gelatine, 0.01 g cm 3 of transglutaminase (mTGase) a minimum of 2 h incubation at 4degC and an additional step of crosslinking with 1.0 vol. of glutaraldehyde. Next, the absorption properties and storage stability of hydrogels so obtained were determined. From these results, it was observed that, with the exception of the physical gel, the remaining materials presented a relatively high resistance to hydrolytic degradation and retained their original spatial structure without any visible damages. The immobilisation experiments indicated gelatine based hydrogels crosslinked with transglutaminase as suitable for use as matrices for the entrapment of enzymes, which catalyse the conversion of low molecular mass compounds. In addition to the potential for effective re use in subsequent batch processes, the essential advantage of the immobilised b galactosidase obtained in the current study is a marked reduction in its volume under storage conditions of long duration, without any significant decline in catalytic activity.
Chemical Papers