STARCH HYDROLYSIS AND FERMENTATION OF SUGARS BY THE ASSOCIATION OF ASPERGILLUS AWAMORI AND SACCHAROMYCES CEREVISIAE MICROBIAL CULTURES IN BIOETHANOL PRODUCTION

Abstract

Subject. Features of starch fermentation technology into bioethanol using association of Aspergillus awamori and Saccharomyces cerevisiae microbial cultures. Purpose. On the basis of comprehensive research, to substantiate the theoretical foundations of starch-containing raw materials preparing for fermentation by developing a resource-saving technology of starch one-stage hydrolysis in the conditions of synergistic relations between the fungus Aspergillus awamori and the yeast Saccharomyces cerevisiae. Methods. The methods and processes for the preparation of starch-containing raw materials, which are generally accepted in the domestic production of ethyl alcohol were used in research. Results. The technological mode of one-stage hydrolysis of starch and fermentation of sugars by the association of the culture of the mycelial fungus Aspergillus awamori and the yeast Saccharomyces cerevisiae without the introduction of extracellular enzymes of the amylolytic complex was experimentally substantiated. It was determined that a mixture of raw materials` ground with water with a hydromodule of 1:3, enriched with urea in the amount of 0.4 g/dm³, orthophosphoric acid in the amount of 0.13 g/dm³, and corn extract in amount of 1 g/dm³, should be considered as a rational conditions for fungi cultivation. It was established that in a mixed culture the process of saccharification and fermentation occurs in one stage and almost simultaneously, while yeast and mycelial fungi compete for the carbon source. Scope of results. The proposed technological solutions will lead to the formation of a different conceptual approach to the bioethanol production development, increasing its efficiency by reducing the cost of purchasing enzyme preparations.