Abstract: In recent years, organic solvents have attracted large avenue of interest to explore the
potential of enzyme to produce highly specific active chemical molecule of industrial advantage. The present
study discerns the role of organic solvents as a reaction medium for enzymatic catalysis. The stability of alpha
amylase in organic medium promises its major application in starch processing food industries and pharmaceutics.
The enzyme appeared to be stable and retained considerable activity in the presence of various aprotic organic
solvents such as acetone, acetonitrile and DMSO. The anomalous behavior of acetone showed concentration
dependent increase in activity with 1.9 times enhancement at 50 % (v/v) concentration. Various polar organic
solvents such as methanol, ethanol, propanol and ethylene glycol showed activation of enzyme except for nbutanol.
Non-polar solvents also activated the enzymatic activity. The n-hexane showed about 1.2 folds activation
at 30 % (v/v) concentration. Further, Cr3+, Al3+, was found to be activator while Cd2+and Ba2+also could not show
any significant inhibitory effect. The sulfhydryl-modifying reagents such as NEM showed activation whereas
partial inhibition occurred in the presence of IAA and pHMB. In addition, PMSF showed moderate activity of
enzyme while urea appeared to be strong inhibitor of enzyme. However, the characteristic properties of stable
alpha amylase in non-aqueous medium have potential utility in non-aqueous enzymology for various
biotechnological processes.