The autoselection of neustonic forms of bacteria]

Self-breeding of neuston forms of Methylobacterium sp., Pseudomonas putida BC-2, Alcaligenes paradoxus BC-1, Bacillus thuringiensis var. israilensis bacteria as well as of a mixed culture of methylotrophs is shown possible. In spite of ability of hydrophobicity of the cell surface the suggested method of self-breeding may be used to perfect properties of larvicidal biopreparations, and bacterial preparations which intensify self-purification of water bodies.     

Formation of purple membranes during salt bacteria cultivation]

Experiments have been carried out on cultivation of halophile with probe selection in the interval of 1--2 hours to record the spectra of repeated disturbed completed inner reflection. Periodicity in the changes of spectral characteristics of the culture with the interval of 20--24 hours is revealed. A clearly expressed dichroism of the amid II band of the membrane complex is found, the absence of this dichroism in the protein isolated from the membrane complex is stated. It is suggested that dichroism revealed is a specific feature of the presence of purpuric membranes in the cells. Spontaneous plane orientation of protein macromolecules in purpuric membranes is established. The level of dichroism of amid II band is shown to depend on fermentation conditions of salt bacteria.     

Adaptation of yeasts and bacteria to antimicrobial substances during continuous-flow cultivation

1. (1)
   Различные методы ад аптации из дрожжей и бактерий к антимикробным веществ, рассматриваются, а также Преимущество использования условий непрерывного потока для определенных целей.     
   
   

Cellular protrusions of luminescent bacteria and relation of their appearance to cultivation conditions]

The luminescent cells of Photobacterium were studied by electron microscopy in order to establish what caused their sticking together and growth on the glass walls of the vessel during continuous cultivation. Electron microscopy revealed protrusions, of various shape and size, on the cells. The phenomenology of various protrusions, including fimbria, is described, and the effect of cultivation conditions (continuous culture, periodic culture) and growth phases on their emergence was elucidated. The sticking of the cells together and their growth on the glass walls were less expressed at pH between 7.5 and 7.9, when the amount of the cells with the fimbria was the least and they were formed during the later phase of growth.     

Oscillation in the number of bacteria during starvation]

Factors stimulating the increase in the numbers of Escherichia coli bacteria and accelerating their death were studied. It was shown that oscillations in the numbers of viable bacteria are due to periodic changes in the activity of these two factors, which do not coincide in phase. The oscillations in cell numbers occur only at particular cell concentrations.     

Directed capture of enzymes and bacteria on bioplastic films

The development of smart coatings for a variety of uses depends on the ability of the coating material to perform specific functions. We have used water dispersible polyurethane preparations for the immobilization of binding proteins under mild conditions. In these experiments, antibodies against the enzyme beta-galactosidase or the bacterium Escherichia coli were immobilized in polyurethane coatings and then used to effectively capture their cognate antigen. Further, a second, more general, capture protocol was developed which involves the incorporation of the protein avidin in the plastics. This system efficiently captures biotinylated beta-galactosidase. Biotinylated anti-E. coli antibody captured by avidin bioplastics resulted in a nearly 5-fold increase in the number of bound bacteria when compared to blank polyurethane. The use of avidin in a bioplastic allows any biotinylated antibody to be applied to all or part of the surface resulting in a patterning of capture agents on a preformed surface.     

Directed isolation of gram-negative asporogenous bacteria from natural substrates

A method for selective isolation of gramnegative nonsporulating bacteria from soil substrates was developed. The method consists of plating out the substrates on a glucose-yeast medium with addition of benzylpenicillin and nalidixic acid. The isolation frequency of gramnegative nonsporulating bacteria increased under such conditions from 9-16 (control) to 80-100 per cent. At the same time the isolation frequency of gram-positive bacteria decreased from 88.5 to 9.6 per cent.     

Mathematical modeling of population dynamics of unstable plasmid-containing bacteria during continuous cultivation in a chemostat

A structural approach to studying the regularities of the population dynamics of unstable recombinant bacterial strains in a chemostat was elaborated. The approach is based on the mathematical modeling of cell distribution in a population with different numbers of plasmid copies. The effect of decreased selective preference of plasmidless variants of the recombinant strain in the chemostat, which is related to a decrease in the number of plasmid copies in cells upon long-term incubation was analyzed. It is shown that the time of half-elimination of plasmids from the bacterial population in the steady state in the chemostat T1/2 does not depend on the maximum number of plasmid copies in cells N but is determined only by the mean time of generation g and the probability of the loss of one plasmid copy tau. The dependence of the preference of bacterial plasmidless variants on the efficiency of expression of genes cloned into plasmids in chemostat was analyzed using the recombinant strain E. coli Z905, whose plasmids pPHL-7 contain cloned genes for the luminescence system of marine luminescing bacteria Photobacterium leiognathi.     

Antigenic activity of Bordetella pertussis during cultivation in liquid nutrient media]

The authors studied the antigenic activity of Bordetella pertussis during stab cultivation. For the first time there were revealed changes (oscillations) of antigenic activity: formation of 3 peaks of which the middle was the highest. A possibility of improving the quality of pertussis vaccine by using biomass at the height of the peak was experimentally founded.     

An experimental study of a modified turbidostat

Summary The efficacy of a modified turbidostat scheme for control of a continuous fermentor supporting substrate - inhibited growth of a methylotroph, L3, was experimentally examined. The control was based on continuous measure of optical density of fermentation broth. The experimental results illustrate the feasibility of the control scheme for effective startup as well as stabilization of a continuous fermentor under the influence of a load disturbance.     

Autoradiographic study of human scirrhous gastric carcinoma during cultivation in diffusion chambers]

The growth of the epithelial and connective tissue cells was noted in cultivation of human schirrous carcinoma of the stomach in diffuse chambers. In difference to the initial tissue of the tumour in vitro in which no incorporation of thymidine-H3 into the connective tissue cells was noted, these cells proved to be labeled under conditions of growth in the chambers. One hour after the administration of thymidine-H3 the percentage of cells with labeled nuclei averaged 25.1% this considerably exceeding the value of the label index determined under conditions of incubation in vitro of the initial tumour tissue (6.6%). Under conditions of cultivation there was revealed a rapidly proliferating subpopulation of cells with the mitotic cycle duration of 14.8 hours.     

Simple digital control of cell mass in turbidostat

Summary The application of simple digital control method to the control of cell mass in a continuous stirred tank bioreactor (CSTBR) was experimentally examined. This algorithm based on the time-varying bilinear predictor model was as simple as proportional-integral-derivative(PID) control algorithm and showed better performance.     

Acquisition and study of callus tissue during cultivation of mazzard and strawberry anthers]

Anters of 7 varieties of Cerasus avium (2n=16) and Fragaria grandiflora (2n==56) were cultured on Murashige-Skoog's medium. Formation of the callus tissue was observed for only one variety of sweat cherry with a frequency of 3.1-20.6%. The number of haploid cells in first transfers varied from 22 to 44% in different strains. There were two rises of mitotic activity in the callus cells. Subsequent transfers caused an increase in haploid cells. Chromosome aberrations frequency was comparatively low. No cases of induced organogenesis on any modifications of the nutrient media were found.