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N A Rodionova

Publications and source records attributed to N A Rodionova.

40 records · Page 3Linked to original sources

[Preparation of cellulolytic enzymes from Geotrichum candidum].

The ability of different fungi cultivated on cellulose to synthesize extracellular cellulase was examined. The fungus Geotrichum candidum str. 3c was the most active among the fungi tested, including Trichoderma fungi. The formation of cellulolytic enzymes in the culture filtrate of G. candidum occurred, when the entire glucose and the major portion of reducing substances were utilized. The formation of cellulases depended on the content of ammonium ions. The enzyme accumulation reached the highest level at the stationary phase of the culture growth and depended on the inoculum amount. When the inoculum was used as a submerged culture at a concentration of 3%, accumulation of C1-enzyme, endo-(1 leads to 4)beta-glucanases, and beta-glucosidases reached maximum by 44, 52 and 56 hours of cultivation. The fats that are frequently used as a foam catcher inhibited the cellulase formation by the abouve strain. From the filtrate cellulolytic enzymes were isolated via spray drying and precipitation with 3 ethanol volumes to yield 6.5 and 5.0 g/l, respectively. The cellulases when stored at 5 degrees C did not lose their activity for a year and became inactivated by 40-50% in 5 years.

Cellulase↗

[Properties of beta-glucosidase from the fungus Geotrichum candidum 3C].

The ability of beta-glucosidase from the fungus Geotrichum candidum 3C to degrade cell oligosaccharides, disaccharides and glycosides was examined. It was demonstrated that the rate of enzymic hydrolysis of cell oligosaccharides depended on the length of the substrate chain. The major product was glucose. The beta-glucosidase purified showed high specificity towards beta-glucopyranosyl and degraded only the glucosides which incorporated beta-glucopyranosyl. The enzyme had a relatively low specificity towards aglycon, and hydrolyzed both disaccharides and aryl-glucosides. The enzyme also showed traansglycosylase activity.

Geotrichum↗

[Purification of exo-1,4-beta-xylosidase from Aspergillus niger 15].

From the preparation of xylanase of the fungus Aspergillus niger 15 exo-1,4-beta-xylosidase was isolated by means of ethanol fractionation and chromatography on columns of Sephadex G-50, cellulose DE-52, Sephadex SP C-50, Sephadex G-200. The isolated enzyme (with the purification degree as calculated per protein 199, and yield with respect to activity 42.5%) was homogeneous during gel filtration, polyacrylamide gel electrophoresis in the presence and absence of Na dodecyl sulfate, ultracentrifugation and isoelectric focusing. Exo-1,4-beta-xylosidase had a molecular mass of 253,000 as shown by gel filtration and 122,000 as shown by Na dodecyl sulfate polyacrylamide gel electrophoresis; its sedimentation coefficient was 10.6 S and isoelectric point was pI 4.9. The specific activity of the homogeneous enzyme was 35.2 u./mg protein with respect to p-nitrophenyl-beta-D-xylopyranoside and 30.2 u./mg protein with respect to xylobiose.

Aspergillus niger↗

[Localization of catalysis enzyme systems that degrade higher plants' cell wall polysaccharides. Pectinases (review)].

This paper reviews recent data on the locations and compositions of enzyme systems catalyzing the cleavage of cellulose, hemicelluloses, and pectin polysaccharides in higher plants. The physiological functions and physicochemical properties of certain enzymes degrading pectin polymers in higher plants, fungi, and bacteria are described.

Carbohydrate Sequence↗