In modern biotechnological practice, there is a growing trend toward the use of thermostable enzymes due to their efficiency in intensive industrial processes. Among the diversity of microbial producers of thermostable glucoamylases, special attention is paid to bacteria of the Bacillus genus (B. licheniformis, B. subtilis, and B. amyloliquefaciens). The aim of this study was to analyze the technological aspects of the process of obtaining the enzyme preparation of glucoamylase. In the present study, strains 1-5 of Bacillus subtilis were selected for the evaluation of amylolytic activity. Quantitative determination of amylolytic activity was performed using a modified iodometric method. The concentration of total protein was determined using the Bradford spectrophotometric method withbovine serum albumin as a standard to construct a calibration curve. The results of this study showed that strains 1, 5, and 3 were characterized by the highest glucoamylase activity. At the same time, bacterial strains 2 and 4 showed a significantly lower level of amylolytic activity. The results of preliminary studies indicate the prospects of using brewer's grains and molasses as cost-effective and nutritious components of the nutrient medium for the cultivation of glucoamylase producers, which provides a complete and balanced substrate for the biosynthesis of enzyme products.