Conditions of enzymatic hydrolysis of plant raw materials pretreated with ultrasound in feed protein technology

The aim of the study was to study the conditions of enzymatic hydrolysis of vegetable non-food cellulose-containing raw materials pretreated with ultrasound in order to obtain easily digestible fermentable sugars in the technology of obtaining feed protein. Cellulose-containing raw materials were used in the work - substandard grain, wheat straw and buckwheat, previously subjected to ultrasonic disintegration with the achievement of a concentration of reducing substances (PB) 9.31 - 10.03 g/l. It was shown that the highest glucose concentration was determined in buckwheat straw fermentolysate when 20 ml of RRF was added during 90 minutes of incubation and amounted to 12.48 g/l. On wheat straw, the glucose concentration of 10.33 g / l is determined by adding 20 ml of PPF for 60 minutes of incubation. The conditions of enzymatic hydrolysis were optimized using the Box-Wilson method with the implementation of the Gauss-Seidahl full factorial experiment (PFE22) and steep ascent. The optimization parameter Y was the glucose concentration, g / l; the factors of variation: x1 - the volume of the working solution of the enzyme (RRF), ml; x2 - the pH of the reaction mixture, units; x3 - the duration of the reaction, min. According to the obtained mathematical model, the optimal conditions for an enzymatic reaction on cereal straw are the use of 20 ml of PPF with a reaction duration of 70 minutes. At the same time, the glucose content in wheat straw fermentolysate is 11.35 g/l; buckwheat straw is 11.54 g/l. The steep ascent can be considered effective, since the result obtained is 53% higher than the theoretically calculated one. As a result of the conditions optimized using mathematical modeling of the previously physico-mechanical and in this study biological methods of destruction of cellulose-containing raw materials, the indicator of "crude" fiber in wheat straw fermentolysate decreased by 92.45%, lignin by 83.3%; in buckwheat straw fermentolysate by 92.69% and 86.20%, respectively. The obtained data formed the basis of the technology for producing feed protein, where a sugar solution based on cellulose-containing waste serves as a component of the nutrient medium for the microbial producer of feed protein - yeast strain Saccharomyces cerevisiae VKPM Y-365.