Smetanska I. Physiological and biochemical fundamentals of biotechnology for obtaining phenolic compounds from plant in vitro cultures

The dissertation work is devoted to the development of sustainable biotechnology for obtaining of phenolic compounds from plant in vitro cultures. The research focuses on investigation of physiological and biochemical processes that have impact on the growth intensity of plant in vitro cultures, on the expression of synthesis of phenolic compounds, and consequently on development of technologies for extraction of metabolites and application components of functional food. This research work represents multi-stage biotechnological process for obtaining functional phenolic compounds. In the course of investigation, the following tasks were accomplished: screening of plants in order to identify those containing high concentrations of phenolic compounds; comparison of the intensity of synthesis of compounds in plants and their in vitro cultures; increasing of phenolic synthesis; development of extraction technology and further application of phenolic compounds as components of functional food with improved organoleptic and technological properties. A direct relationship between the content of phenolic compounds and the antioxidative activity of extracts has been proven. Changing the nutrient medium, adding precursors and elicitors also influenced the antioxidative properties of in vitro culture extracts. Methods for improving the taste and increasing the stability of food products enriched with phenolic compounds during storage have been developed and proposed. A comprehensive assessment analysis of application of in vivo and in vitro technologies has shown, that the process of obtaining phenolic compounds from plants grown in a greenhouse reached index 3.45, cell cultures 7.49, hairy root cultures 7.71 and shoot cultures 8.37. The yield of phenolic compounds from shoot cultures was 106 times higher than that of intact plants. Within the framework of the provided systematic analysis of the impact of cultivation conditions on the physiological and biochemical parameters of in vitro cultures and optimization of extraction technologies, a complex biotechnology for the obtaining of phenolic compounds from in vitro cell, hairy roots and shoot cultures S. rebaudiana, V. vinifera, and O. aristatus has been developed. At the same time, it was proved that the influence of all methods and technologies used in this research work was tendentiously similar, but not identical for the cultures studied. Therefore, further all steps of this complex biotechnology need to be adapted for each particular practical application, depending on the physiological and biochemical properties of plants and their in vitro cultures as well as on the technological characteristics of the final products.