Chromatographic purification of the enzyme preparation from the cultural liquid of Pleurotus ostreatus

The primary purification of the proteolytic enzyme preparation from the Pleurotus ostreatus culture fluid was carried out. Methods of salting out, dialysis, ion-exchange chromatography on DEAEand KM-sepharose were used. It was shown that during the chromatography on KM-sepharose, the enzyme preparation from the culture liquid was divided into three fractions, one of which possessed milk-clotting activity (МСА). Chromatography on DEAE-sepharose allowed us to reach the significant purity of the enzyme with МСА.

SELECTION OF THE COMPLEX OF ENZYME PREPARATIONS FOR THE HYDROLYSIS OF GRAIN CONSTITUENTS DURING THE FERMENTATION OF THE WORT OF HIGH CONCENTRATION

In this paper, an optimal complex is selected of enzyme preparations for hydrolysis of the components of grain raw materials during fermentation of high concentration wort. When selecting enzyme systems, their effect on the technical and chemical parameters of the fermented wash during the fermentation of wort is investigated. For the research, maize grain with a starch content of 69.0 % was used. Fermentation was carried out with 18–30% of dry matters (DM) in the wort, using the osmophilic yeast strain Saccharomyces cerevisiae DO-16.The recommended concentration of the enzyme preparation Amylex 4 T (the source of the α-amylase enzyme) – 0.4–0.6 units of α-amylase ability/g of starch – is optimal for the concentration 18–27% of DS in the wort. For 30 % of DS, it is practical to use 0.6 units of α-amylase ability/g of starch. With the use of the enzyme preparation Diazyme TGA (the source of the enzyme glucoamylase), the value is 7.5 units of glucoamylase ability/g of starch, alcohol accumulation in fermented washes was 10.51, 13.35, 15.78% vol., according to the wort concentrations 18, 27, 30 %, respectively. It has been established that with the application of the cytolytic enzyme Laminex 750, the concentrations of dissolved carbohydrates and non-dissolved starch have a tendency to decrease. In the samples where the proteolytic enzyme preparation Alphalase AFP was added at a concentration of 0.05 units of proteolytic ability/g of raw materials, there was an increase in the accumulation of yeast cells by 6.5% compared with the reference sample. The recommended concentration of Deltazyme VR XL (the source of β-glucanase and xylanase) is 0.05 units β-glucose/g of raw materials. The addition of a cytolytic and proteolytic enzyme preparation in combination with β-glucanase and xylanase contributed to an increase in the accumulation of ethanol in the washes by 1.7 % compared with the reference sample, and to an almost 33 % decrease in the concentration of dissolved carbohydrates and non-dissolved starch. On the basis of experimental studies, it has been found that using a complex of enzyme preparations – amylolytic (Amylex 4T), saccharifying (Diazyme TGA), proteolytic (Alphalase AFP), cytolytic (Laminex 750), and complex AF β-glucanase and xylanase (Deltazyme VR XL), in various combinations of their concentrations, – contributed to the intensification of the fermentation process of the wort and increased accumulation of the target product, ethanol, by 0.8–1.4 %, depending on the wort concentration. The highest amount of ethanol accumulated at the maximum dosage of additional enzyme preparations.

STUDIES ON A PROTEOLYTIC ENZYME IN HUMAN PLASMA

1. Some conditions for the optimal activation of plasma proteolytic enzyme by chloroform have been described. The activation proceeds slowly. The action of chloroform is probably to remove some substance which inhibits or inactivates the plasma proteolytic enzyme preparation, rather than a direct activation of the enzyme. 2. Plasma proteolytic enzyme is activated by filtrates of cultures of beta hemolytic streptococci. When streptococcal fibrinolysin is present in maximally effective amounts, the activation is almost instantaneous. When the globulin is prepared from heated serum or the globulin is treated with chloroform, the activation of enzyme by streptococcal fibrinolysin appears to be catalytic. If the globulin is not so treated, the reaction appears to involve a stoichiometric process. 3. The plasma proteolytic enzyme activated by chloroform or by streptococcal fibrinolysin digests casein in direct proportion to the concentration of enzyme and to the time of digestion, during the early period of incubation. 4. Fibrinolysin-activated enzyme deteriorates rapidly relative to chloroform-activated enzyme. This may be due to the removal by chloroform of some substance which inactivates plasma proteolytic enzyme.