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Biomedical subjects

Z A Arkad'eva

Publications and source records attributed to Z A Arkad'eva.

14 recordsLinked to original sources
PubMed1991

[Microorganisms oxidizing maleic acid in sewage].

The bacteria of genera Pseudomonas oxidizing maleic, fumaric, italic acids and their anhydrides in sewage of industry of maleic anhydride have been isolated from active sludge. During the autoselection a strain of P. stutzeri 832 capable to oxidize 12.5 - 25.0 g/l of maleic acid on 90 - 70% correspondingly in 3 days has been isolated. Destructive activity of isolated strain was retained after 5-year storage in lyophylized state and under vaseline oil.

Culture Media↗
PubMed1983

[Factors affecting the viability and properties of microorganisms in different preservation methods].

The review of literature devoted to the influence of the different methods of longterm preservation on the survival, physiological and biochemical properties of microorganisms: at low and ultralow temperatures, freeze-drying, drying, storage under the mineral oil etc. is given. The microorganisms viability depends on their nature, age and density of population, storage and recovery conditions of cells. Some features of the industrial microorganisms storage have been marked. The different hypotheses concerning the mechanism of preservation, injury and reactivation of microorganisms under the action of external factors during their storage are being discussed.

Bacterial Physiological Phenomena↗
PubMed1983

[Preservation of lactic acid bacteria].

The lyophilized Streptococcus lactis, S. cremoris, S. diacetilactis, Lactobacillus bulgaricus, L. casei C10, L. caucasicus cultures have had a great number of viable cells after 4 years storage. L. casei and S. cremoris strains endured 3 months storage at -30 degrees C and in the sterile vaseline oil for 8 months. After storage S. cremoris strains showed the high level of the lactic acid formation and of proteolytic and lipolytic activities.

Freeze Drying↗
PubMedDate not supplied

[Comparison of methods of storing lactic acid bacteria].

The study was undertaken to elucidate how different methods of storage (immersing in mineral oil, lyophilization, and subculturing) of lactic acid bacteria belonging to the genera Lactobacillus and Lactococcus affect their viability, antibiotic activity, and ability to accumulate organic acids. Storage of the lactic acid bacterium L. lactis subsp. lactis by immersion in mineral oil proved to be ineffective. Lyophilization allowed the survival of a sufficiently large number of cells, although their antibiotic activity somewhat decreased. The resuscitation of lyophilized bacteria by subculturing them in rich nutrient media, such as skim milk, led to the restoration of their physiological activity, including the effective antimicrobial spectrum.

Culture Media↗
PubMedDate not supplied

[Effect of lyophilization on the nitrogenase activity of Azotobacter vinelandii].

The activity of nitrogenase in the cells of Azobacter vinelandii grown from lyophilized and non-lyophilized cultures depends on the donor of hydrogen and the concentration of oxygen in the gaseous phase. The lyophilized cells are more sensitive to oxygen (O2 optimum for nitrogen fixation is ca. 1 percent) than the non-lyophilized cells (ca. 5 percent). The determination of acetylene reduction in the course of the culture growth has shown that nitrogen fixation in the lyophilized cells takes place after a lag-period (about six hours) at a rate lower than that of the non-lyophilized cells. The results obtained suggest that lyophilization increases the sensitivity of the cells to oxygen and decreases their nitrogenase activity which is however restored after a while.

Aerobiosis↗
PubMedDate not supplied

[Aniline oxidation by microorganisms in chemostat cultivation].

Under the conditions of chemostat cultivation, a mixed culture of microorganisms oxidized aniline at a gradually increasing concentration (up to 2.5 g/litre) as a sole source of carbon and nitrogen. The specific rate of aniline oxidation was as high as 160 mg per 1 g of dry biomass when aniline concentration in the growth medium was 2.5 g/litre. As aniline concentration in the growth medium was gradually raised, selection of the microorganisms took place and the number of the strains decreased from ten to two. The growth rate of the microorganisms fell down abruptly when phosphorus concentration in the medium was below 35 mg per 1 g of aniline.

Alcaligenes↗
PubMedDate not supplied

[Viability of the R, S and M variants of Mycobacterium lacticolum under various preservation conditions].

The survival rate of Mycobacterium lacticolum and the proportion between its R, S and M variants were studied in the course of 12 months under different conditions of storage (freeze-drying, under vaseline oil, in 0.85% NaCl solution and in distilled water). A high survival rate of the variants was found in cells freeze-dried in a protective medium containing 10% of sucrose +1% of gelatin as well as in a 0.85% solution of NaCl.The survival rate of te variants differed by 2--3 orders of magnitude in cells freeze-dried with sodium glutamate or suspended in distilled water. The proportion between the R, S and M variants in the population noticeable changed after storage under these conditions.

Freeze Drying↗
PubMedDate not supplied

[Preservation of lyophilized cultures of saprophytic microorganisms].

All of the tested saprophytic microbial cultures remained viable upon 11--16 years of storage in the lyophilized state at 3--6 degrees. The cultures belonged to the following taxonomic groups: Acetobacter, Achromobacter, Azotobacter, Bacillus, Chromatium, Escherichia, Flavobacterium, Lactobacillus, Micrococcus, Proteus, Propionibacterium, Pseudomonas, Rhizobium, Sarcina, Serratia, Streptococcus, Torula, Mycobacterium, Actinomyces. The number of viable cells in the tubes decredased only slightly within this time and remained at the same level as immediately after lyophilization.

Bacterial Physiological Phenomena↗