Partial purification and characterization of amylase enzyme under solid state fermentation from Monascus sanguineus

Abstract

Amylase is an important enzyme having a varied range of industrial applications from food to cosmetics, from pharmaceutical to detergent industry, etc. The present study was carried out considering these important applications of amylase enzyme. <i>Monascus sanguineus</i> also has not been explored for its efficiency to produce amylase enzymes under solid state fermentation. In the present study, various substrates were screened and among them beetroot as a solid substrate has given maximum yield (0.029 U/mL). Enzyme activity was further optimized by response surface methodology (RSM) and maximum experimental yield of 0.014 U/mL was obtained at optimized conditions of pH 5, incubation temperature of 50 °C and 10 min incubation time. A MATLAB software package was used for the graphical and regression analysis of the experimented data. Enzyme kinetics was calculated with different concentrations of starch and observed K_m value was 0.055 mM from linear regression analysis. The enzyme was moderately inhibited (44.7%) by NaCl and KCl (0.105 U/mL) with minimum inhibition (14.8%) observed with SDS. Molecular weight calculation and amylase confirmation in protein sample was done by SDS-PAGE and Zymography. Calculated molecular weight was 56 kDa. Alkaline amylase produced by <i>M. sanguineus</i> has exhibited high efficiency towards removal of stains on cloths in combination with commercial detergent (Surf excel) at 20 °C. It can be concluded that the fungus <i>M. sanguineus</i> is a good source of amylase production under solid state fermentation. Application of amylase produced by <i>M. sanguineus</i> in detergent industry was also carried out and it was proven very effective in stain removal from the fabrics.