Increased thermal stability of Bacillus licheniformis α-amylase in the presence of various additives

The influence of various additives such as polyhydric alcohols, sugars, polyethylene glycol, and substrates on the thermostability of Bacillus licheniformis α-amylase has been studied. Results obtained showed a thermostabilizing effect of most of the additives tested (ethylene glycol, glycerol, sorbitol, glucose, maltose, maltotriose, and polyethylene glycol). The stabilizing efficiency appears to be strongly dependent on additive concentration. α-Amylase thermostability has also been assayed in organic solvents. In these media, particularly in octane, α-amylase acquired a remarkable stability since no deactivation occurred at 75°C for at least 90 min .