In order to obtain feed enzyme preparations with increased activity of endo-carbohydrases of depolymerase action, mutagenesis of the Trichoderma reesei strain was carried out using ultraviolet and ionizing irradiation. Application of fractionated UV-irradiation made it possible to increase the endoglucanase activity by 20% and xylanase activity by 80% compared to the original strain. The greatest effect was achieved after multistage gamma-irradiation mutagenesis with a cobalt source. When the mutant T. reesei-Co-44 was cultured in shaking flasks, its endoglucanase activity was increased 5-fold, while xylanase activity increased more than 8-fold compared to the original strain. High activity of the target enzymes in the mutant strains was confirmed by the results of fed-batch cultivation in laboratory reactors with lactose feeding as a carbon source and an inducer of cellulases and xylanases biosynthesis. The maximum activity of endoglucanase and xylanase was achieved by culturing strain T. reesei-Co-44 obtained as a result of gamma-irradiation mutagenesis and amounted to 1324.2 ± 70.1 and 3394 ± 164 U/mL, respectively. This activity level makes it possible to produce competitive enzyme preparations of carbohydrases for fodder production.

In order to improve the biosynthesis of amylolytic enzymes by industrial Aspergillus strains, the efficiency of stepwise application of the following methods of induced mutagenesis was studied: ultraviolet (UV) irradiation, gamma irradiation, and treatment with N-methyl-N-nitro-N-nitrosoguanidine (NG). It was found that at the early stages of mutagenesis of the glucoamylase-producing A. awamori strain UV and NG, used either alone or in combination, were efficient enough as mutagenic agents, providing an increase of glucoamylase activity by 30–35 and 50–60%, respectively. At the later stages, serial UV mutagenesis and gamma-irradiation showed high efficiency for both A. awamori, and A. oryzae strains. Gamma-mutagenesis of Aspergillus strains using a cobalt source provided the most stable and highly active strains retaining 90–95% of their activity after five transfers on agar medium. The experiments resulted in significant improvement of the studied industrial strains, more than doubling activity of the target enzymes.

С целью повышения пищевой и кормовой ценности шрота подсолнечника были проведены исследования по его комбинированной биоконверсии с применением термомеханической экструзии и ферментативной обработки препаратами целлюлолитического и протеолитического действия. Методом рототабельного композиционного планирования, в котором управляющими факторами являлись концентрация субстрата и дозировки ферментных препаратов, было установлено, что повышение концентрации сухих веществ в реакционной смеси при гидролизе экструдированного шрота подсолнечника способствует повышению степени гидролиза некрахмальных полисахаридов и затрудняет гидролиз белка до легкоусвояемых растворимых пептидов с молекулярной массой ниже 10 кДа. Максимальные достигнутые концентрации продуктов гидролиза в условиях опыта (12-12,5 мг ВС /г СВ и 245-250 мг растворимого белка/г СВ) соответствовали максимальным дозировкам соответствующих ферментных препаратов. Показано, что экструзионная предподготовка шрота подсолнечника обеспечивает повышение концентрации ВС на 51,5% и растворимого белка на 15,1% по сравнению с гидролизатами неэкструдированного шрота подсолнечниками.