Endo-N-acetylglucoseaminidase (EC 3.2.1.30) was prepared from the cultural broth of Streptomyces levoris 96 using precipitation with ammonium sulfate, gel filtration on Sephadex G-25 and ion exchange chromatography on DEAE-cellulose. The isoelectric point of the enzyme is 4.2 Str. levoris produces various quantities of the enzyme depending on the composition of the growth medium. A medium in which the enzyme is produced in maximal amounts has been selected. The effect of peptidoglycan, cell walls and chitin added to the medium on the enzyme biosynthesis was studied. Chitin induced biosynthesis of the enzyme by 35--45%.

The results are presented of experimental studies of hepatic cytosol, nucleus and chromatin hormone-receptor activity of animals with decreased enzyme induction of gluconeogenesis, resultant from prolonged cortisol injection. In such animals in vivo 3H-cortisol incorporation into hepatocyte subcellular fractions was changed, being reduced in cytosol and enhanced in microsomes, nuclei and chromatin. 3H-Cortisol incorporation into chromatin was the highest in combination of the experimental rat hepatic nuclei with cytosol of intact animals after in vitro incubation with reconstructed homogenate labelled hormone from hepatocyte nuclei and cytosol. After incubation of experimental and intact rat nuclei with cytosol of the animals under study 3H-cortisol binding in chromatin was 30% lower than after incubating the nuclei with cytosol from intact rats.

The phenotype of skeletal-muscle cells of a chick embryo in the primary monolayer culture maintained in the full medium (80% of the Eagle medium, 15% of serum, 5% of embryonic extract) and in the poor one (85% of the Eagle medium, 15% of serum) has been studied using both light and electron microscopy. In the full medium culture, which served as a control, the fusion of myoblasts (the index of fusion 51%) with the consequent formation of muscles fibers was observed. These fibres were able to contract and their ultrastructure was typical for differentiated skeletal-muscle cells. In the medium without an embryonic extract, the fusion of myoblasts was suppressed (the index of fusion 6%). The monolayer fibroblast-like cells lacking characters of differentiated muscle cells and, unlike, having those of typical fibroblasts were most numerous. The transference of myogene cells into fibroblast-like ones is reversal : after the substitution of the poor medium by the full one, both cell fusion (the index of fusion 45-47%) and differentiation of cell fibres are observed.

The synthesis of exoproteases and cephalosporin C in Acremonium chrysogenum is repressed by easily assimilated forms of nitrogen and carbon according to the type of nitrogen metabolism repression and catabolism inhibition. Glucose and ammonium salts inhibited the mycelium fragmentation and prevented formation of conidia. Amino acids had a diverse effect on the synthesis of the proteases and antibiotic. Methionine played the role of an inductor of the synthesis of alkaline exoproteases, cephalosporin C and the mycelium fragmentation into arthrospores.

Preincubation of cells in the presence of 4% ethanol accompanied by an increase of non-saturated cis-vaccenic acid content was shown to promote synthesis of alkaline phosphatase. Preincubation of cells in 0.1% hexanol reducing the level of this acid, on the contrary, leads to partial repression of the enzyme synthesis; the lag-phase of repression in the cells with a raised content of non-saturated cis-vaccenic acid and, consequently, with a greater fluidity of lipids was also shown to be reduced. Conversely, the reduction of lipid membrane fluidity on ethanol addition simultaneously with the repressing metabolite ortho-phosphate extends the lag-phase of repression and removes it partially during cell cultivation in the presence of ortho-phosphate. The impact of lipid composition variations on the synthesis and repression of alkaline phosphatase is discussed.

Administration of ascorbic acid at moderate doses/0.05-0.1 g per kg of body mass/was shown to induce tyrosine transaminase in liver tissue of intact rats. The enzyme induction depended on the state of adrenal glands and was inhibited by actinomycin D. As distinct from the native form of L-ascorbic acid moderate doses of D-isoascorbic acid did not induce the enzyme in rat liver tissue; these data suggest the relative biological inactivity of D-isoascorbic acid.

Exposure of Cephalosporium acremonium, strain 1435, to N-nitrozo-N-methylbiuret resulted in a changed variation coefficient with respect to two quantitative features--the antibiotic production and proteolytic activity. Correlation between the variation coefficient and mutagen exposure time was different for every feature. Positive correlation was found in variation with respect to the antibiotic production and proteolytic activity in populations of various Cephalosporium acremonium strains chosen with regard to one or two of the above features. The level and form of the correlation in variation of the above features in populations changed during selection. Selection according to the two quantitative features resulted in an increased correlation coefficient.

The difference in the growth on fructose between differentiated and adifferentiated variants of Streptomyces roseoflavus var. roseofungini should be attributed to their different capacity in forming the enzyme system for fructose uptake whose action is induced by this carbohydrate. In the cells of the two variants grown on glucose and mannitol, the process of induction occurs in the presence of chloramphenicol. In the cells grown on glycerol, chloramphenicol inhibits the induction. The growth of the differentiated variant on fructose stops apparently due to the exhaustion of endogenous reserves which are necessary for maintaining the system of fructose uptake in the active state.

Combined induction of liver monooxygenases with 3-methylcholanthrene (3-MC) and phenobarbital (PB) has been studied in experiments on DBA/2 and C57B/6 mice. As is known, PB increases the number of intracellular receptor sites for polycyclic hydrocarbons. When DBA/2 mice resistant to the induction were pretreated with PB, there were no signs of induction common to those induced by 3-MC. In similar experiments with the sensitive C57BL/6 mice, PB and 3-MC produced additive effects on the induction of liver monooxygenases.

The synthesis of luciferase and the dynamics of luminescence were studied in the course of batch cultivation of the strain 54-K obtained from the wild strain of Photobacterium mandapamensis after numerous passages. Luciferase synthesis bvy the strain was not sensitive to the inhibitor contained in the growth medium and did not require the accumulation of an "audoinductor". Since the intensity of luminescence and the content of luciferase per cell did change, the bacterium seemed to possess an additional system for regulating the synthesis of luciferase which was independent of the "autoinductor" and the inhibitor.

A mutant strain of Trichoderma viride producing cellulase has been obtained as a result of three-stage selection using chemical and physical factors. New variants with modified characteristics appeared after the action of nitroso compounds on a suspension of conidia at the first stage of selection and the action of temperature at the second stage. The new characteristics were intensified and became stable at the third stage of selection. The experimental mutagenesis yielded an active an active mutant of Trichoderma viride 44 which synthesized cellulase (up to 22 units/ml) four times better than the parent culture Trichoderma viride F-57.

The content of cytochrome P-450 was studied in the cells of alkane oxidizing yeasts Candida guilliermondii, C. tropicalis and C. lipolytica. The cells of all the studied yeast strains growing on hexadecane were found to contain cytochrome P-450. The cytochrome was not detected when the yeast strains grew on glucose. The concentration of cytochrome P-450 remained constant at the exponential growth phase, but decreased at the beginning of the stationary growth phase. Cytochrome P-450 was shown to be synthesized de novo in the course of physiological adaptation of the cells to hexadecane.

The biological rhythm of the transition from the processes of blocking and nuclear division to active RNA biosynthesis and growth in submerged culture of Aspergillus awamori producing glucoamylase was studied by the technique of quantitative cytochemistry, and was characterized by distinct daily oscillation in a medium with starch. The rhythm was disturbed when other carbon sources, viz. maltose, sucrose and particularly glucose, were used: the rhythm became longer and uneven, the rate of nuclear blocking decreased, and the de novo formation of the mycelium of the adaptive stage capable of producing glucoamylase was inhibited. As we have shown earlier, such rhythms in fungi are induced at the level of nuclear processes; in this study, they were most affected by the disturbances which led to the inhibition of the enzyme production. It is quite possible therefore that the processes of biochemical adaptation in fungal ontogenesis, particulaly the production of hydrolytic enzymes, are regulated at the molecular-biological level in the initiation of their synthesis rather than at the level of competition between the existing pathways of general metabolism, and are closely related to biorhythms.

The localization of exoproteinase in the conventionally "periplasmic" space of Bacillus thuringiensis was established. The enzyme located at the outer surface of the membrane was found, in the course of sporogenesis, within the spore where it could fulfill various functions. The role of glutamine synthetase was determined in the regulation of exoproteinase synthesis and sporogenesis. The both processes were inhibited in the conditions suppressing the activity of glutamine synthetase.

The effect of phosphate and acetate buffer systems on the growth of Gluconobacter oxydans and its synthesis of levansucrase was studied in nutrient media containing sorbitol. The intensification of constructive processes in media with an increased content of phosphate did not accelerate the enzyme biosynthesis by G. oxydans. As was shown in experiments with the intact cells of G. oxydans, the respiratory activity of the bacterium was stimulated in phosphate buffer supplemented with fructose. In contrast, acetate inhibited fructose oxidation and hindered the growth. At the same time, the synthesis of levansucrase increased. Such an increase was also found when the growth of G. oxydans was suppressed by sodium fluoride, an inhibitor of cellular metabolism. The extra synthesis of levansucrase useless during the growth on sorbitol should be attributed apparently to non-balanced growth of the bacterial culture caused by the suppression of respiration processes.