[Chemical mutagenesis and the use of indirect enzymatic criteria for the selection of virulent clones of Bacillus thuringiensis].

The effect of the mutagene nitrosoguanidine (N-methyl-N'-nitro-N-nitrosoguanidine) on the growth of Bacillus thuringiensis subsp. galleriae st. 69/6 was being studied.

Influence of the conditions of growth on the chemical composition and activity of the enzymes of the cell envelope of the yeast Candida tropicalis IBFM-303.

The article is devoted to a study of the changes in the activity and chemical composition of the enzymes of the cell envelope of the yeast Candida tropicalis IBFM-303 during growth on n-alkanes and glucose, as well as the transport of n-alkanes through the cell membrane and the redistribution of the cell contents in the process of budding on the indicated carbon sources.

[L-glutaminase-asparaginase biosynthesis by a Pseudomonas boreopolis culture dependent on cultivation conditions].

The activity of deamidases of L-glutamine and L-asparagine of Pseudomonas boreopolis 526 was found to depend on the conditions of cultivation. The activity of L-glutaminase-asparaginase II (EC 3.5.

[Physiological and biochemical properties of Actinomyces kurssanovii, active producter of chitinase].

Chitinase biosynthesis by Actinomyces kurssonovii 75 was studied under conditions of periodic cultivation in a laboratory fermenter. The activity of components of the chitinolytic complex correlated with the growth phases of the culture. The activity of chitobiase (beta-N-acetylglucoseaminidase) predominated in the cultural broth in the exponential growth phase of the culture; it decreased later by 40-50 per cent, while the activity of chitinase became maximum.

[Several properties of the extracellular vesicles of Candida tropicalis yeasts grown on n-alkanes].

Vesicles with a high content of phospholipids were found when Candida tropicalis IBFM-303 was cultivated on n-alkanes. The vesicles were extracellular, and their inner content had a fine-grained structure confined within a monolayer membrane. The number of the vesicles increased in the course of growth and depended on the concentration of n-alkanes in the medium.

[Chitinase of Bacillus thuringiensis].

Strains of Bacillus thuringiensis were shown to hydrolyse various forms of chitin around growing colonies on a solid medium. In conditions of submerged cultivation on a medium containing demineralized crab shells, Bac. thuringiensis var.

[Purification and properties of L-glutamine and L-asparagine deaminase from Pseudomonas aurantiaca IBPM-14].

An enzymic preparation of L-glutamine and L-asparagine deamidase was obtained from Pseudomonas auractiaca IBPM B-14. The preparation was purified 100--150-fold by thermal treatment and chromotography on columns with biogel P-150 and DEAE-cellulose. The enzymic activity was measured by the methods of hydroxylaminolysis and direct nesslerization.

[Chitinase from Serratia marcescens BKM B-851].

The chitinase biosynthesis was studied during the cultivation of the strain of Serratia marcescens BKM B-851 with a high chitinolytic activity. Under submerged cultivation of bacterial cells on the medium containing demineralized crab shell extracellular chitinase showed maximum activity on the 3rd day. Cells of S.

[Biosynthesis of chitinase by Achromobacter liquefaciens].

Bacterial cultures under study synthesize exocellular chitinase on a medium containing chitin or demineralized crab shells as a source of carbon and nitrogen. Conditions for biosynthesis of chitinase by the cells of Achromobacter liquefaciens 301a were investigated under periodic and continuous conditions of cultivation. The preparation of chitinase isolated from the cultural broth of A.

[Formation of L-asparagine and L-glutamine deamidases by bacterial cultures].

Among studied 40 bacterial cultures, 17 strains catalysed hydroxylaminolysis of I.-asparagine and L-glutamine, and among these cultures seven strains belonged to the Pseudomonas genus. Extracts of the cells of Ps.

[Activation of L-amino acids by aminoacyl-tRNA-synthetases from yeast Candida utilis IBPM-405].

The procedure for isolating aminoacyl-tRNA-synthetases from yeast Candida utilis IBPM-405 was developed. The rate of activation of L-amino acids in the formation of hydroxamates was different. Aspartic acid, asparagine, glutamic acid, tryptophane, phenyl alanine and methionine underwent the highest activation.

[Physiologo-biochemical characteristics of Candida tropicalis yeasts, cultivated on n-alkanes at supraoptimal temperature].

Cultivation of Candida tropicalis IBEM 303 without thermostatic regulation on n-alkanes results in an increase of the temperature in the fermenter to supraoptimal values and to the linear growth of the culture without distinct differentiation according to the growth phases. The cells grown at supraoptimal temperature differ from the cells cultivated at optimal temperature by the amount of some amino acids and oligopeptides liberated by the yeast into the cultural broth, by the chemical composition of the cells and their morphology.