Effect of Surfactants on the Biosynthesis of Alpha Amylase by Bacillus Subtilis Gcbm-25

The present study was concerned with the selection of suitable surfactant for the production of alpha amylase by Bacillus subtilis GCBM-25 in 250 ml shake flask containing 50 ml of fermentation medium. Different surfactants (laundry soap, detergent powder, sulphonic acid, acyle benzene sulphonic acid, liquid soap, Tween 80, sodium silicate, bath soap, sodium tripolyphosphate, sodium lauryl ether sulphate or sodium lauryl sulphate) @ 2.0 % (w/v) were tested for enzyme production. Of all the surfactants, laundry soap gave better production of alpha amylase (605 U/ml/min) 44 h after inoculation (4.0 % inoculum size). The production of enzyme was found to be optimum (857 U/ml/min) when Millon soap @ 3.2 % (w/v) was added to the medium. The thermostability of the enzyme was decreased from 70 to 50C as the surfactant was added to the fermentation medium.