Production, properties and application of saccharomyces cerevisiae VGSH-2 inulinase

Experimental data on an acid and thermal inactivation of a high refined inulinase (2,1-β-D- fructanfructano-hydrolase, KF 3.2.17), produced by the race of Saccharomyces cerevisiae VGSh-2 yeast are presented. The strain of S. cerevisiae VGSh-2 was produced by the method of the induced mutagenesis and deposited to the collection of pure cultures of the chair of biochemistry and biotechnology of Voronezh state university of engineering technologies. The cells of source culture ( S. cerevisiae XII) were affected step-by-step by the ultra-violet radiation (UFR) and UFR in a complex with a chemical mutagen (etilenimine). The culture was grown up by the method of liquid-phase deep cultivation on a constant nutrient medium. Refining conditions for inulinase are sorted out. Activity of enzyme dependence on physical and chemical factors (рН and temperature) is obtained and numerical values of the main kinetic constants - K m and V max are determined. The structure of enzyme molecule is studied by an infrared-spectroscopy method: the type and relative quantity of elements of secondary structure of protein are defined. Substrate binding groups of the active center of an inulinase are found. The comparative analysis of the ability to hydrolysis of inulin in several enzyme preparations from Jerusalem artichoke and to the subsequent their fermentation by the VGSh-2 and XI S. cerevisiae yeasts is carried out. Optimum conditions of enzyme hydrolysis of inulin are selected. Research of the fermentation process of starch-containing raw materials by yeasts of VGSh-2 and XI races is done. It is established that the using of VGSh-2 S. cerevisiae yeast for a grain wort and the Jerusalem artichoke fermentation, allows to increase an extraction of ethyl alcohol comparing to control race, to improve its quality characteristics, and also allows to predict the using of new race in the food industry for production ethanol from grain raw materials and a fermentation of inulin containing raw materials.