Development of nutrient medium composition for obtaining a protein-enzyme complex from rapeseed meal

Currently, the industrial cultivation is becoming unprofitable due to the use of expensive synthetic nutrients, so it is necessary to look for new components that meet market demands. The prices of hydrolysates of plant raw materials, such as soy flour, have increased almost tenfold in the last 5 years. The search for new sources of raw materials and technological solutions for the production of nutrient components is the main direction of development for biotechnologists. In the territory of the Russian Federation, rapeseed plantings from 2017 to 2022 grew more than twice: from 1 million hectares to 2.3 million hectares and there is an increase in the volume of crops sown for the year 2024. The processing of rapeseed cake and meal is a priority task facing the scientific community. By utilizing biotechnological solutions, production cycles do not generate waste, and the target products do not contain anti-nutritional substances (erucic acid, glucosinolates with degradation products). The purpose of this study is to develop a nutrient medium based on rapeseed cake hydrolysate for obtaining a protein-enzyme complex as a feed additive. This article discusses the optimization of the rapeseed cake fermentation process and the design of media for cultivating industrial producers of Bacillus subtilis. The samples of target products obtained after biotransformation showed high growth characteristics when using laboratory-scale media models.