Production and Optimization of Amylase and Glucoamylase from Aspergillus Niger under Solid State Fermentation for Effective Production of Glucose Syrup

Abstract

The continual demand for sugars, coupled with the chemical hazards associated with chemically produced syrup, has led to the development of enzymatic technology, which has increased the production of glucose syrups, especially using enzymes from microbial origins. The aim of this work was to isolate, screen, and optimize the best cultural conditions for producing glucose syrups from Nigerian cassava starch using enzymes produced by soil microorganisms. Additionally, proximate and physiochemical properties of glucose syrup produced from yellow and white maize using microbial enzymes were determined. The results obtained from the preliminary screening showed that most of the isolates obtained were Aspergillus niger. It was observed that Aspergillus niger had the largest zone of amylase activity of 35.0 mm when compared to Fusarium pallidorosium, which had the lowest (5.0 mm). The optimal conditions for enzyme production—temperature, incubation period, inoculum concentration, and pH—were 30°C, 5 days, 1 × 10⁶ CFU/ml, and pH 5, respectively, for the production of glucoamylase and amylase. Generally, strain AMO1 was observed to produce more glucoamylase compared to amylase. The crude protein, color, viscosity, ash content, reducing sugar content, pH, and carbohydrate contents of the syrup from yellow maize were higher than those of the syrup from white maize.