Experiment to study some suspension media for the lyophilization of actinomycetes]

Viability and cultural properties of 59 actinomycetes and 17 bacteria lyophilized in polyvinylpyrrolidone (PVP), sodium glutamate, their combinations and horse serum were studied after storage for 2 years at a temperature of 4-10 degrees. A 5 per cent solution of sodium glutamate had a high protective effect on viability of the above organisms. The solution containing 3 per cent of sodium glutamate and 3 per cent of PVP was somewhat less effective. The cultures lyophilized in 5 per cent solution of sodium glutamate had the same viability levels as those lyophilized in horse serum, while the latter had better growth rates on their plating out on nutrient media. A 5 per cent solution of PVP had no advantages over sodium glutamate or horse serum with respect to preservation of the organism viability. No significant differences in the cultural properties: colour of the aerial and substrate mycelium and pigment production were noted in the actinomycetes lyophilized in various protective media and the analogous control cultures maintained by means of passages on fresh nutrient media.     

Transition of entheropathogenic and saprotrophic bacteria in the niche cycle: Animals-excrement-soil-plants-animals

The possibility of transition of saprotrophic and enteropathohenic bacterial populations following the chain of naturally related habitats—fodder-animal gastrointestinal tract (GIT)-animals excrement-soil-plants and again animals with a cyclic formation—has been investigated quantitatively. All bacteria used in the experiments have been shown to successfully overcome all the mechanical, physical-chemical, and biological barriers in the food chain and to come out into the environment with a quite high number. It has been demonstrated that the same bacterial population can pass the whole cycle without additional introduction of similar populations from the outside.     

Response of identified mollusk neurons to treatment with certain metabolic regulators during different oxygen supply conditions

The time course of redox systems of some identified Helix pomatia neurons and their bioelectrical activity during exposure to cAMP and prostaglandin E2 under normoxia and anoxia was studied by means of a complex technique on the basis of contact vital microscopy. It was discovered that neuronal response to the substances was uncertain under varying conditions of neuronal oxygen supply. In the presence of preliminary exposure to cAMP and prostaglandin E2 the character of shifts in redox systems and bioelectrical activity occurring in the neurons during oxygen deprivation was to be changed.     

Cytological study of spontaneous embryonic mortality before implantation in mice of different genotypes

Spontaneous preimplantation embryonic mortality was studied cytologically for mice of different strains and their combinations. It was found that this index was determined to a considerable extent by the genotype. Its level varied from 5 to 10% depending on the genotype. The stoppage of embryos' cleavage and, probably, their death occurs mostly at the stage of 2-12 blastomeres.     

Stereological analysis of myocardial structures in plastic heart insufficiency

Electron microscopy, morphometry and stereological analysis were used to examine structural components of the myocardium of Wistar rats after injection of the anthracycline antibiotic rubomycin. Using the determination of absolute summary weights of cardiomyocytes, interstitial connective tissue, vessels and intercellular space as well as of the volume and surface densities of these structures the development of involutional atrophic lesions in the myocardium was demonstrated. The connective tissue showed an increase in the population of fibroblasts, diffuse activation of protein synthesis in them and collagen synthesis de novo. The genetic relationship between abnormal regeneration of cardiomyocyte ultrastructure (plastic heart insufficiency) and diffusive cardiosclerosis is established.     

Monitoring of beetles associated with fungi using Kaila traps

In the present work, we tested the possibilities of using modified window-flight Kaila traps for studying insects associated with fungi. Criteria allowing us to reveal the character of association between an insect and fungus have been developed. We analyzed the association between Staphylinidae and a species of polypore fungi. We assessed the suitability of Kaila traps for studying beetles associated with fungi, as well as their selectivity; we give recommendations on their use.     

Kinetics of the generation of a photo-induced electric potential in chromatophores of photosynthetizing bacteria

Flash-induced formation of an electric potential difference (delta psi) was monitored by a direct method in chromatophores associated with the collodion phospholipid membrane. In Rhodospirillum rubrum and Rhodopseudomonas sphaeriodes chromatophores, the kinetics of delta psi generation exhibit fast (tau less than or equal to 0.3 microseconds) and slow (tau congruent to 200 microseconds) phases, the latter observed in the presence of exogenous quinones. Comparison of the kinetic and potentiometric characteristics of the process with those of electron transport reactions suggests that the fast phase of delta psi rise is due to charge separation between the primary electron donor, P870, and primary electron acceptor QIFe; the slow phase, which is inhibited by o-phenanthroline, is due to electron donation from QIFe to the secondary acceptor, quinone QII. The kinetics of delta psi decay include components arising form the recombination of primary separated charges (tau congruent to 30 ms) and from the passive discharge of the membrane (tau congruent to 400 ms; tau congruent to 1400 ms). From a redox titration of the photo-induced electric signal and the photo-induced absorption changes of P870 at different pH meanings, the value of pK for the primary acceptor FeQI was found to be 7.4 in Rps. sphaeroides chromatophores. In Chromatium minutissimum, a phase ( tau congruent to 20 microseconds) was observed in addition to those seen in Rps. sphaeroids and R. rubrum which was explained by the reduction of P890+ from the high potential cytochrome c555. Possible distribution of the electron transport components in the chromatophore membrane are discussed.