[Preparation of cellulolytic enzymes from Geotrichum candidum]. / Poluchenie tselliuloliticheskikh fermentov iz 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.

[Optimization of the conditions for beta-galactosidase biosynthesis in eukaryotes]. / Optimizatsiia uslovii biosinteza beta-galaktozidavy u éukariotov.

Liquid whey can be subsituted by dry whey in the growth medium for Saccharomyces fragilis producing endocellular beta-galactosidase. The total biosynthesis of beta-galactosidase by the yeast on the medium containing dry whey can be increased by 40-50 percent as a result of additional stepwise introduction of lactose into the medium or optimization of the medium by mathematical planning of the experiment. Constructive metabolism of the yeast is not correlated with the rate of biosynthesis of beta-galactosidase. Damages in constructive metabolism of facultative anaerobes - yeast cultures - caused by the limitation of aeration result in an increase of the rate of beta-galactosidase biosynthesis. Such a correlation between the rate of the enzyme biosynthesis and the degree of aeration of the culture is not found in strict aerobes - fungi Alternaria tenuis and Curvularia inaequalis.