Production of α-amylase from some thermophilic Aspergillus species and optimization of its culture medium and enzyme activity

Abstract

This paper aimed to evaluate the thermophilic and hyperthermophilic fungi isolated from extreme conditions capable of secreting α-amylase, an enzyme that has a commercial value especially in the production of bread in the food industry and also to ensure their optimization. In this study, thermostable amylase activities of some thermophilic Aspergillus species were evaluated. The suitable medium and microorganisms for α-amylase synthesis were selected. Subsequently, the α-amylase activity of the microorganism was researched. In the measurements made on the 7th day of production on respectively Aspergillus niger, Aspergillus oryzae, Aspergillus terreus cultures produced at mycological, stock basal medium (SBM) and starch yeast extract liquid medium in order to determine a more efficient medium for amylase activity, the α-activity observed was 1.83, 1.66 and 0.75 U/ml in the mycological liquid medium, 2.37, 2.28 and 1.69 U/ml in the SBM medium and 6.8, 5.9 and 5.1 U/ml in the starch yeast extract liquid medium. The optimum temperature (65°C) and the optimum pH 8, respectively, and activity of α-amylase enzyme obtained from A. niger showed the highest activity level.

Keywords: Aspergillus, enzyme activity, thermophilic fungi, α-amylase