Assimilation of animal fats by yeasts and synthesis of protein by continuous cultivation in a complex nutrient medium

Under the conditions of continuous cultivation studies were carried out on a mixed culture (association) with two strains of yeasts: Candida sp., assimilating animal fats, and Candida scottii, assimilating reducing sugars. A complex nutrient medium of wood hydrolysate was used. It was established that in this medium, at a rate of dilution of D = 0.25 h^?1, the mixed culture assimilates the fats and the sugars simultaneously. As a result of this the yield of absolutely dry yeasts with regard to the total sum of fats and sugars amounts to 71% in the case of incineration fat and to 82% in the case of technical pork fat. The contents of protein, amino acids, lipids and ashy substances in the yeasts obtained from a medium with fats do not differ substantially from those obtained from the same medium without fats.     

Enhancement of chloroplast energization in Chlorella by treatments inactivating the nitrate-reducing system

Inactivation of the nitrate-reducing system in whole cells of Chlorella vulgaris Bejerinck by darkening, nitrogen starvation, ammonium, or cycloheximide brings cells into a state with a high yield of the millisecond-delayed fluorescence of chlorophyll. Activation of this system by illumination, by adding glucose to dark-adapted cells or nitrate to nitrogen-starved cells brings the cells into a low-yield state. The transitions between the lowand high-yield state induced by alternating light and dark periods are suppressed by tungstate and restored by subsequent molybdate addition. The drop in the delayed-fluorescence yield upon activation of the nitrate-reducing system is associated with the decrease of the amplitude of the electrochemical proton gradient across the thylakoid membrane of the chloroplast, as evidenced by the kinetics of the light-induced adsorption changes at 520 nm. The decrease of the proton gradient may be caused by the electron flow diverting from the cyclic path in photosystem I as a result of the activation of the electron transfer from ferredoxin to nitrite.Abbreviation DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea     

Activity of propriospinal neurons in segments C3 and C4 during fictitious locomotion in cats

Activity of propriospinal neurons in segments C3 and C4 was recorded in immobilized decerebrate cats, whose spinal cord was divided at the lower thoracic level, during locomotor activity of neuronal mechanisms controlling the forelimbs (fictitious locomotion of the forelimbs). Neurons were identified according to antidromic responses to stimulation of the lateral column of the spinal cord at level C6. Antidromic responses also appeared in 70% of these neurons to stimulation of the medullary lateral reticular nucleus. During fictitious locomotion, i.e., in the absence of afferent signals from the limb receptors, rhythmic modulation of the discharge of most neurons was observed, correlating with activity of motoneurons. If the rostral region of the cervical enlargement of the spinal cord was cooled, causing generation of the locomotor rhythm to cease, rhythmic activity of propriospinal neurons in segments C3 and C4 also ceased. The main source of modulation of activity of propriospinal neurons in segments C3 and C4 is thus the central spinal mechanisms controlling activity of the forelimbs.Institute for Problems in Information Transmission, Academy of Sciences of the USSR, Moscow. M. V. Lomonosov Moscow University. Translated from Neirofiziologiya, Vol. 17, No. 3, pp. 320–326, May–June, 1985.     

Aberrations of cortical and subcortical integration during chronic administration of haloperidol to the dog

The character of evoked potentials (EPs) dynamics to signal light stimulus during elaboration of avoidance reaction, allows to assert that during formation of adaptive activity functional balance is established of sensory and integrative-triggering brain parts or functional balance of "motor" and "sensory" integration regimes. Each of the studied subcortical structures is characterized by simultaneous but specific functioning both in the motor and sensory regimes; such conclusion is based on different dynamics of their EPs parameters: the changes of ones correspond to EPs dynamics in the visual cortical area, of the others--in the motor area. During chronic haloperidol administration, the reorganizations of intercentral relations are observed in 10--12 days after the beginning of drug administration. They may be considered as a succession of disturbances of functional balance between "sensory" and "motor" integration regimes: at first the sensory regime domination appears in which subcortical structures are chiefly and uniformly involved (ncd, pall and n. acc.); "motor" regime is weakened; then, as a result, a distortion of the "motor" regime of integration takes place. In this case a bradykinesia is developed.     

Stability of rifamycin B in aqueous solutions

Stability of rifamycin B in aqueous solutions at various values of pH and temperature was studied. It was shown that inactivation of the antibiotic in neutral and alkaline solutions proceeded according to the first order equation. In acid solutions rifamycin B was oxidized with air oxygen to form rifamycin O.     

Monitoring the seeds of chronically irradiated indigenous populations of Plantago lanceolata L. Variability in the progeny

The results of the morphometric study of Plantago lanceolata L. grown, in nursery, from seeds of the first and second post-accident reproductions within the thirty-kilometer zone around the crippled Chernobyl reactor show no relationship between the alterations in some quantitative indices and the variability of gamma-radiation background in places where maternal plants grow.     

A cytogenetic study of the human chorion for the purpose of the prenatal diagnosis of hereditary diseases

Cytogenetical investigation of 50 diagnostic chorionic villus samples from women with a high risk of giving birth to babies with chromosomal and genic pathology, and of 128 chorionic samples obtained from medical abortions, both on the 8-12th weeks of gestation was performed by means of original direct chromosomal analysis. Chromosomal anomalies were found in 6 cases of diagnostic chorion biopsies (12%) and in 4 cases (3%) of medical abortions. The former group included 5 embryos with autosomal trisomy (4--Ts21 and 1--Ts13) and one embryo with monosomy 18. The latter group contained 2 embryos with X-chromosome monosomy and 2 other with chromosomal mosaicism. A significant prevalence of the female sex was found in the diagnostic group (sex ratio 0.56), but not in the medical abortion one (sex ratio 1.0). Analysis of routine chromosomal preparations and those after in situ hybridization with X-chromosome alfoid-probe YAP 1-10 revealed polyploidy in average in 0.8-1% chorion cells. The feasible causes of sex ratio distortion in embryos of diagnostic group and factors responsible for the rate of polyploidy are discussed. High reliability of originally elaborated direct "shaking-blotting" method of chromosomal preparations from chorionic villus samples is stressed.     

Analysis of long-latency components of field potentials evoked by stimulation of the cerebral cortex and nerves in the cerebellar paramedian lobule

Field potentials evoked in the graunular layer of the cerebellar paramedian lobule of unanesthetized cats in response to stimulation of the sensomotor cortex and limb nerves contained slow negative waves, appearing after a long latent period, which were generated by granule cells. In the case of nerve stimulation this component was recorded both inside and outside the projection zone of the corresponding limb. Cortical stimulation by single stimuli or series of stimuli not more than 1.8–2.5 times above threshold strength led to the appearance of evoked potentials only inside the corresponding projection zone. The long-latency component of field potentials evoked by cerebral stimulation followed high frequencies of repetitive stimulation and was less sensitive to the action of barbital anesthesia than the analogous component of potentials evoked by nerve stimulation. In the case of combined cerebral and nerve stimulation the long-latency components underwent summation. It is concluded that mossy fibers of slowly-conducting spino- and cerebrocerebellar tracts innervate different granule cells in the cerebellar cortex.Institute of Problems in Information Transmission, Academy of Sciences of the USSR, Moscow. M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 14, No. 4, pp. 379–385, July–August, 1982.