Optimization of amylase activity in the presence of various metal ions and surfactants in aqueous system

Zulfiqar Ali Raza and Aisha Rehman

Abstract

The effect of Fe+2, Mg+2, Ca+2 cations, and sodiumdodecylsulphate (SDS) and  cetyltrimethlyammonium bromide (CTAB) surfactants was investigated on amylase activity in the  aqueous media. Three commercially available enzymes (Luzyme HP, Aquazym SDL, Bactosol PHC) were used for this purpose under various setups. In the first setup, individual effect of metal ions and surfactants was studied, and then based on the results from first setup; in the second setup, trend of amylase activity was studied for a concentration range of selected metal and surfactant. The third experimental setup was conducted to study combined effect of metal ions and surfactant on amylase activity. In case of metal ions, Fe2+ ions showed promoting effect on amylase activity. CTAB inhibited amylase activity whereas SDS promoted it up to certain level.  Moreover, the effect of Fe2+ ions and SDS concentration on activity was found that Fe2+ enhanced activity up to 5 mM while SDS concentration didn’t show considerable effect. Combination of both Fe2+ and SDS showed increment in activity up to a certain level. All three commercially available amylases showed almost similar behavior towards metals and surfactants; however, the activity of Bactosol PHC was the highest than others.



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