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

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. Monascus sanguineus 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 M. sanguineus 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 M. sanguineus is a good source of amylase production under solid state fermentation. Application of amylase produced by M. sanguineus in detergent industry was also carried out and it was proven very effective in stain removal from the fabrics.