Evidence for the improvement of thermostability of the maltogenic alpha-amylase of Aspergillus niger by negative pressure.

Thermostability of the enzymes is influenced by the different parameters and pressure also
influences the biological activity of the enzymes. Recently reported maltogenic a-amylase
from Aspergillus niger acts optimally on starch at 408C and it was unstable above 408C at
atmospheric pressure. Calcium could stabilize the maltogenic a-amylase activity up to 508C
at atmospheric pressure. But, at negative pressure (�200 mbar) enzyme was stable at
temperatures higher than 508C either in the presence or absence of the substrate, starch
making it adoptable for starch processing. Enzyme showed higher affinity to the starch at
negative pressure compared to the atmospheric pressure and change in the surface roughness
of the enzyme is almost similar to the native state at 708C and negative pressure. These
results suggest that thermolabile enzymes can be used at negative pressures for industrial
applications.