Immobilisation of Aspergillus oryzae alpha-amylase and Aspergillus niger glucoamylase enzymes as cross-linked enzyme aggregates

摘要

Cross-linked enzyme aggregates (CLEA) of Aspergillus oryzea a-amylase (AoAA) and Aspergillus niger glucoamylase (AnGA) were prepared using glutaraldehyde and dextran polyaldehyde as crosslinkers. The maximum activity recoveries for glutaraldehyde cross-linking were 21.8 % and 41.2 %, respectively. The addition of a proteic feeder (bovine serum albumin) exhibited a negative effect on the activity recoveries for both enzymes. Dextran polyaldehyde was used as a cross-linking agent instead of glutaraldehyde to reduce the activity losses. As a result, an activity recovery of 60.0 % was obtained for Aspergillus oryzea a-amylase. On the other hand, no activity recovery was observed for Aspergillus niger glucoamylase due to the latter enzymes affinity for dextran.(C) 2014 Institute of Chemistry, Slovak Academy of Sciences