A. Vikartovska-welwardova et al., Stabilization of D-amino-acid oxidase from Trigonopsis variabilis by manganese dioxide, FOL MICROB, 44(4), 1999, pp. 380-384
Stabilization of immobilized D-amino-acid oxidase was achieved as follows.
Yeast Trigonopsis variabilis producing D-amino-acid oxidase was used to dea
minate cephalosporin C to glutaryl-7-aminocephalosporanic acid. Permeabiliz
ed cells were co-immobilized with manganese dioxide by entrapment in (poly)
acrylamide gel so that hydrogen peroxide, liberated in the reaction, could
be partially deactivated and both the enzyme and the substrate could be sta
bilized. Activity of entrapped cells was determined by HPLC and enzyme flew
microcalorimetry. The process was evaluated in terms of activity, immobili
zation yield, storage stability and oxo-product Formation by immobilized pr
eparations. The storage stability of immobilized bicatalysts with MnO2 was
nearly doubled and production of 2-oxoadipyl-7-aminocephalosporanic acid wa
s 2-3-fold higher than by entrapped cells without MnO2. Glutaryl-7-aminocep
halosporanic acid can be easily obtained from the resulting ore-product by
a non-enzymic reaction via externally added hydrogen peroxide.