Biomedical subjects

A G Kisten'

Publications and source records attributed to A G Kisten'.

5 recordsLinked to original sources

PubMedDate not supplied

[Effect of gas mixture component composition on the process of hard materials colonization by methanotrophic bacteria].

A device has been proposed which allows decreasing a possibility to contaminate the inoculum of methane-using bacteria (methanotrophs) under its growing. The gas mixture composition has been investigated for the intensity of grass and polysterene colonization by two species of methanotrophs: Methylococcus capsulatus UCM B-3030, possessing hydrophilic surface and hydrophobic Methylocystis parvus UKM B-3490T. It has been shown that immobilized methanotrophic bacteria can colonize the above materials in the wide range of methane and oxygen concentrations in gas mixture. The process of hard materials colonization was most intensive when the mixture contained 17-28% of methane and 5-28% of oxygen. No essential differences have been registered under colonization of hydrophilic (glass) and hydrophobic (polysterene) materials by the both cultures.

Biofilms↗

PubMedDate not supplied

[Physiological activity of mixed cultures of Methylcoccus capsulatus UKM B-3030 with Bacillus megaterium UKM B-5723T and Bacillus subtilis VKPM B-1489 on solid surface colonization].

Physiological activity of monoculture of Methylococcus capsulatus UCM B-3030 and its mixed cultures with two bacilli species distinguished by proteolytical properties--Bacillus megaterium UCM B-5723T and Bacillus subtilis BK[symbol: see text]M B-4189 in terms of long-duration cultivation is investigated. It is shown, that the most active methane consumption by methanotrophic bacteria and their mixed cultures with bacilli under solid surface colonization occurred on the second-eighth day of cultivation. The obtained results permit one to evaluate intensity of CH4 oxidation process by typical microflora of some econiches (depleted coal mines, in particular).

Bacillus megaterium↗

PubMedDate not supplied

[Features of solid materials' colonization by pure and mixed cultures of methanotrophs].

The process of colonization of hydrophilic (glass) and hydrophobic (polysterene) carriers by pure cultures of methanotrophs Methylocystis parvus UCM B-3490T, Methylococcus capsulatus UCM B-3030, as well as by their cultures mixed with Bacillus megaterium UCM B 5723T and Pseudomonas putida VKPM B-4188 under the conditions efficient for methanotrophic bacteria. M. parvus demonstrated the highest intensity of this process on the above carriers owing to high hydrophobic cell surface. Both methanotrophs colonized the glass surface more quickly with formation of microcolonies on carriers after 6 days of incubation in pure and mixed cultures with B. megaterium. The number of bacilli on these carriers quickly decreased. In the mixed cultures with P. putida the glass and polysterene colonization intensity decreased, while the amount of pseudomonas on carriers increased.

Bacillus megaterium↗

PubMedDate not supplied

[Soil microflora over the closed Donbas mines].

Composition of soil air and microflora in different soil horizons (to 30 cm depth) over some closed Donbas coal mines has been studied. The intensive methane leakages have been found in some soil zones over the closed coal mines. This results in formation of explosive and inflammable gas mixtures. Methane content in soil gas mixtures could vary from trace amounts to 34 %. The essential decrease of oxygen (to 3-4%) and increasing (up to 5 %) of CO2 concentrations that evidences for active microbiological processes in such soils is marked in the latter case. Methanotrophic bacteria involving methane into biogenic cycle are widespread (up to 106 cells per 1 g) in methane-containing soils over the closed coal mines. Microorganisms of different physiological groups in the community with methanotrophic bacteria were found in the given technogenic econiche.

Coal Mining↗

PubMedDate not supplied

[The effects of several factors on the growth of pure and mixed cultures of Azotobacter chroococcum and Bacillus subtilis].

We studied the effect of a clay mineral, palygorskite, on the physiological activity of Azotobacter chroococcum and the phosphate-mobilizing bacterium Bacillus subtilis, as well as their mixed cultures, under various oxygen supply conditions during the utilization of phosphorus from readily and poorly soluble compounds (K2HPO4 x 3H2O) and (Ca3(PO4)2), respectively. During cultivation of the bacteria in a nutrient medium with Ca3(PO4)2, the number of microorganisms was higher than that observed in a medium with K2HPO4. An increase in oxygen mass transfer in the nutrient medium was followed by a rise in the number of Bacillus subtilis cells and an inhibition of Azotobacter chroococcum growth. An addition of palygorskite (5 g/l) into the nutrient medium stimulated the growth of both bacteria and stopped the decreasing growth of Azotobacter chroococcum at high values of oxygen mass transfer. The number of Bacillus and, particularly, Azotobacter cells was two to five times lower in a mixed culture than in a monoculture. These differences were less significant during the cultivation of mixed cultures in medium with palygorskite.

Azotobacter↗