Optimisation of fungal glucoamylase production by Response Surface Methodology and characterisation of the purified enzyme

Tapasi Polley,Uma Ghosh

doi:10.14719/pst.2020.7.3.762

Abstract

A statistical approach was made for the production of glucoamylase by Aspergillus niger using wheat bran and green gram as fermentation medium. Box-Behnken design used to analyse the simultaneous impact of the substrate, hydration, inoculum volume, fermentation time and temperature, using a second-order polynomial. The experimental results were in good agreement with the proposed regression model with R2 = 0.9322 (p<0.05). The maximum yield (313 U/gds against the predicted value of 306 U/gds) was obtained using 12 gm substrate, 55% moisture, 1 gm sucrose and 0.05 gm tryptone. The purification and characterisation of the enzyme were also studied. Optimum thermal and pH stability was 60 °C and 5 respectively.

Highlights

Starch-degrading enzymes such as glucoamylase have applications for dextrose production, confectionery, baking and in pharmaceuticals [1].Glucoamylase hydrolyses starch producing glucose as sole end-product
The present study explores the optimisation of fermentation parameters statistically to get a better yield of glucoamylase produced by Solid-state fermentation (SSF) and the optimisation of glucoamylase production by SSF using response surface methodology (RSM) and characterisation of the partially purified enzyme
To make the enzyme production cost-effective agricultural residue wheat bran and green gram mixture were studied as the medium for the production of glucoamylase

Summary

Introduction

Starch-degrading enzymes such as glucoamylase have applications for dextrose production, confectionery, baking and in pharmaceuticals [1].Glucoamylase hydrolyses starch producing glucose as sole end-product. A statistical approach was made for the production of glucoamylase by Aspergillus niger using wheat bran and green gram as fermentation medium. The maximum yield (313 U/gds against the predicted value of 306 U/gds) was obtained using 12 gm substrate, 55% moisture, 1 gm sucrose and 0.05 gm tryptone. To design the fermentation process with a maximum production of an enzyme, optimisation of these physical parameters is much needed.

Results

Conclusion