[The role of low-molecular-weight nitrogen compounds in the osmotolerance of Rhodococcus erythropolis and Arthrobacter globiformis]. / Rol' nizkomolekuliarnykh azotistykh soedinenii v osmotolerantnosti bacterii rodov Rhodococcus i Arthrobacter.

Investigations showed that Rhodococcus erythropolis E-15 and Arthrobacter globiformis 2F cells respond to osmotic shock by increasing the synthesis of free amino acids, primarily glutamic acid (80% of the intracellular free amino acid pool). The osmoprotective role of glutamic acid follows from its beneficial effect on the growth of bacteria in high-salinity media. It was found that the addition of this amino acid to the growth medium at a concentration of 2 mM shortened the lag phase and increased the growth rate and biomass yield of either of the two bacteria. The addition of another osmoprotectant, trehalose, to the high-salinity growth medium of R. erythropolis E-15 at the same concentration (2 mM), restored the growth parameters of this bacterium to the control values.

[Bacterial succession on n-alkanes under the conditions of sulfate reduction]. / Bacterial'naia suktsessiia na n-alkanakh v usloviiakh sul'fatreduktsii.

The dynamics of species composition of a hydrocarbon-oxidizing bacteriocenosis of a ground suspension of Mozhaisk Reservoir has been studied. The bacteriocenosis was undergoing development in a paraffin film (model association composed of sulfate-reducing bacteria and hydrocarbon-oxidizing bacteria). The type of bacterial succession did not depend on the depth, from which ground samples were collected. Two microbial species (Pseudomonas sp. and Arthrobacter globiformis) were absolutely dominant. Pseudomonas sp. was dominant at the early and intermediate stages of the succession, whereas A. globiformis was present in the hydrocarbon-oxidizing bacteriocenosis throughout the whole period of the succession. There was a trend toward a gradual increase in the ratio of A. globiformis, and, by the end of the experiment, Pseudomonas sp. was replaced by A. globiformis almost completely. The bacterial species Micrococcus sp. and Rhodococcus erythropolis were minor components of the hydrocarbon-oxidizing bacteriocenosis under the conditions of sulfate reduction. The succession of species of hydrocarbon-oxidizing bacteria in the paraffin film of the model association reflects both the life strategy of the bacterial species under study and the degree of their tolerance to products of sulfate reduction.

[Extracellular metabolites of hydrocarbon-oxidizing bacteria as a substrate for sulfate reduction]. / Vnekletochnye metabolity uglevodorodokisliaiushchikh bakterii kak substrat dlia razvitiia sul'fatreduktsii.

The relationship between bacterial oxidation of hydrocarbons and sulfate reduction was studied in the experimental system with liquid paraffin was used as a source of organic compounds inoculated with silt taken from a reservoir. Pseudomonads dominated in the hydrocarbon-oxidizing silt bacteriocenosis. However, Rhodococcus and Arthrobacteria amounted to not more than 3%. Arthrobacteria dominated the microbial association formed in the paraffin film of the model system. Sulfate-reducing bacteria were represented by genera Desulfomonas, Desulfotomaculum, and Desulfovibrio. The growth of sulfate-reducing bacteria in media containing with paraffin, successive products of its oxidation (cetyl alcohol, stearate, and acetate), and extracellular metabolites of hydrocarbon-reducing bacteria was studied. The data showed that sulfate-reducing bacteria did not use paraffin or cetyl alcohol as growth substrates. However, active growth of sulfate-reducing bacteria was observed in the presence of stearate and extracellular water-soluble or lipid metabolites of Arthrobacteria.

[Inclusion of labeled precursors of macromolecular compounds in the mycobacterial cells in the presence of DP-2 preparation]. / Vkliuchenie mechenykh predshestvennikov makromolekuliarnykh soedinenii v kletki mikobakterii v prisutstvii preparata DP-2.

The changes in the inclusion of 3H-phenylalanine, methyl-3H-thymidine, [2-14C]-thymidine and [5-3H]-uridine in the cells of pathogenic M. bovis-8, opportunistic M. fortuitum and saprophitic M. phlei, M. B-5 were comparatively investigated in introduction of 0.01 and 0.10% concentrations of the drug DP-2. It is shown that 0.10% DP-2 completely stops the radionuclides supply to the cells. It is suggested that the target of the drug may exist in the sphere of amino acid biosynthesis. The presence of DP-2 is capable of disturbing transport of substances to the cells.

Investigation of the lipids of saprophytic mycobacteria in the U.S.S.R.

Three trends in the investigations of the specific lipids of rhodococci and related microorganisms are reflected: isolation and structural determination of new complex lipids, elucidation of the role of specific lipids in the cells and application of lipid composition for diagnostic studies of rhodococci and related organisms. Two groups of peptidolipids, differing in chromatographic mobility and peptide chain structure, have been found in the cells of Rhodococcus erythropolis. The compounds within each group differ in acyl moieties. Three peptidolipids of the polar group include glucose, so they are peptidoglycolipids. Glycolipids are represented by trehalose derivates. Trehalose dimycolate (cord factor) is dominant. Data concerning the role of lipids in typical features of rhodococci as the lipophilic cell wall, the ability to up-take a hydrophobic substrate and the resistance to influences from outside are given. Examples of application of mycolic acid composition in taxonomy of rhodococci and morphologically similar bacteria are given.

[Hydrocarbon-oxidizing microflora from the water of the Baltic sea and Kurshsky bay polluted after a fuel oil spill]. / Uglevodorodokisliaiushchaia mikroflora akvatorii Baltiiskogo moria i Kurshskogo zaliva, zagriaznennykh pri razlive mazuta.

Microbiological studies were conducted in the water of the Baltic sea and the Kurshsky bay polluted with mazut as the result of a tanker wreck in November 1981 as well as in the water of nonpolluted regions. Within the summer of 1982 and 1983, 755 bacterial strains were isolated from water samples taken at three different depths. Bacteria belonging to the genera Pseudomonas, Rhodococcus + Mycobacterium and Arthrobacter predominated in the hydrocarbon-oxidizing cenoses of the Baltic sea and the Kurshsky bay. The central part of the Baltic sea pure from mazut did not differ from the polluted regions in the qualitative composition of the hydrocarbon-oxidizing bacterial flora. Rhodococci and mycobacteria prevailed in the water near harbours, and pseudomonades, in the open waters. The greatest variety of species was found at a depth of 1 m. The proportion between the predominating genera of hydrocarbon-oxidizing bacteria was not stable. The state of studies conducted with the hydrocarbon-oxidizing microflora is analysed and the factors causing discrepancies are discussed. One must keep in mind that it is necessary to use a strictly elective medium and to examine cultures with a microscope many times throughout their growth in the isolation and identification of hydrocarbon-oxidizing bacteria. The interrelationship is analysed between the predominant genera of hydrocarbon-oxidizing bacteria.

[Biological activity of a polar lipid of Clostridium butyricum spores]. / Biologicheskaia aktivnost' poliarnogo lipida spor Clostridium butyricum.

A fraction of polar lipids was isolated from spores of the anaerobic bacterium Clostridium butyricum 35/11 exerting a noticeable radioprotective effect. The main biological activity of spore extracts was associated with this fraction. The fraction of polar lipids inhibited autolysis of the bacterial cell walls. The fraction was found to contain a phenolic glycolipid and a peptide component. The bacteriostatic and radiotherapeutic properties of the fraction are presumed to be due to its membranotropic activity.

[Esterase activity of hydrocarbon-oxidizing bacteria]. / Esteraznaia aktivnost' uglevodorodokisliaiushchikh bakterii.

The activity of esterase was studied in bacteria oxidizing hydrocarbons and belonging to the genera Rhodococcus, Arthrobacter and Pseudomonas. Indophenyl acetate was used as a substrate of the reaction catalysed by the enzyme. Exocellular esterases were not found. Endocellular esterases differed in their activity and thermostability both among the genera and among species of one and the same genus.

[Free mycolic acids of the cells of coryneform and Nocardia-like bacteria]. / Svobodnye mikolovye kisloty kletok nekootorykh korinepodobnykh i nokardiopodobnykh bakterii.

The composition of free mycolic acids was studied in the cells of Brevibacterium ammoniagenes ATCC 6871, B. flavum 22, B. stationis ATCC 14403, Corynebacterium divaricatum ATCC 14020 and Rhodococcus maris IMV 195. The acids are a mixture of saturated and unsaturated compounds with the total number of carbon atoms from 32 to 36 and the number of C atoms in the alpha-chain from 10 to 15.

[Bacterial interaction in a culture containing Pseudomonas and Mycobacterium in relation to hydrocarbon oxidation]. / Vzaimodeistvie bakterii v kul'ture, soderzhashchei Pseudomonas i Mycobacterium, v sviazi s okisleniem uglevodorodov.

An experimental association of Pseudomonas and Mycobacterium was employed for a more complete oxidation of a hydrocarbon substrate. The maximum effect of combined cultivation (74% vs. 50 and 47% in the pure cultures of Mycobacterium and Pseudomonas, respectively) was obtained under steady-state conditions. The result is attributed to the processes of co-oxidation and the physiological properties of the microorganisms.

[Chemical composition and role of Pseudomonas aeruginosa peptidoglycolipid in hydrocarbon assimilation]. / Khimicheskii sostav i rol' peptidoglikolipida Pseudomonas aeruginosa v protsesse usvoeniia uglevodorodov.

Pseudomonas aeruginosa P-20 releases a lipophilic compound during growth in a medium with hexadecane. The compound was shown to be a peptidoglycolipid. The peptide moiety consists of 7 amino acids: lysine, aspartic and glutamic acids, serine, proline, valine and leucine. The carbohydrate component is ramnose. The lipid moiety is represented by a mixture of fatty acids with the number of carbon atoms from 11 to 18 among which C11:1, C16:0, C18:1 and C17:3 predominate. The content of unsaturated acids is 64.62%. The peptidoglycolipid stimulates the process of hydrocarbon assimilation.

[Role of emulsification in the process of hydrocarbon absorption by Pseudomonas aeruginosa cells]. / Rol' émul'girovaniia v protsesse pogloshcheniia uglevodorodov kletkami Pseudomonas aeruginosa.

Lipophilic biopolymers from the cell walls of saprophytic mycobacteria were shown to stimulate the process of hydrocarbon assimilation by Pseudomonas aeruginosa cells. This should be attributed to the fact that bacterial peptidoglycolipids emulsify a hydrocarbon facilitating the contact between it and the cells. It has been found experimentally that P. aeruginosa cells growing in the medium with n-alkanes release a factor into the medium. The factor appears to contain peptide chains and is responsible for hydrocarbon emulsification.

[Effect of petroleum hydrocarbons on the viability of cyanobacteria in association with oil-oxidizing bacteria]. / Vliianie neftianykh uglevodorodov na zhiznesposobnost' tsianobakterii v assotsiatsii s nefteokisliaiushchimi bakteriiami.

An important aspect in the problem of interactions between microorganisms in the conditions of oil pollution is how to preserve the viability of phototrophic organisms if active oil-oxidizing microflora is present in the environment. As was illustrated using a closed model ecosystem, the association 'cyanobacteria--oil-oxidizing bacteria' is capable of withstanding the negative effect of oil pollution, but within the range of hydrocarbon concentrations which can be oxidized by oil-oxidizing bacteria during a very short time. The biological equilibrium in the ecosystem was maintained and the number of viable cells of the phototrophic component in the ecosystem increased if the oil-oxidizing bacteria started to function at the same time as toxic compounds commenced to produce their effect on the microorganisms.

[Lipids of a paraffin-oxidizing strain of Pseudomonas aeruginosa]. / Lipidy parafinokisliaiushchego shtamma Pseudomonas aeruginosa.

The qualitative and quantitative composition of lipids was studied in a paraffin-oxidizing Pseudomonas aeruginosa P-20 strain. The content of free lipids was 7% of the dry biomass weight in a medium with hexadecane and 6.7% in a medium with glucose. The content of bound lipids was 6.7 and 5.6%, respectively. Phospholipids and free fatty acids are main components of lipids in the both cases. Phospholipids are represented by diphosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidyl glycerol, and phosphatidyl choline. The fatty acids of free lipids consist by 72% of even acids with an unbranched carbon chain, among which palmitic and octadecenic acids prevail no matter what is the composition of a medium. 'Uneven' acids are represented mainly by nonadecenic acid: 17.8% in the medium with hexadecane and 15.9% in the medium with glucose. The content of unsaturated acids is 55.95% in 'hexadecane' cells and 44.89% in 'glucose' cells; octadecenic and nonadecenic acids predominate among unsaturated acids. Fatty acids covalently bound to cellular proteins and polysaccharides contain much less unsaturated compounds (particularly in cells grown in the medium with hexadecane) and more branched acids; C18:1, C16:0 and C17:0-branched acids predominate among them.

[Chemotactic reactions of a paraffin-oxidizing strain of Pseudomonas aeruginosa]. / Khemotakticheskie reaktsii parafinokisliaiushchego shtamma Pseudomonas aeruginosa.

The reactions of chemotaxis were studied in a paraffin-oxidizing Pseudomonas aeruginosa strain using the method of migration in viscous media. Diesel fuel and paraffin become attractants only if they are contaminated with hydrocarbon-oxidizing mycobacteria. A suspension of mycobacterial cells as well as their lipids (peptidoglycolipids, wax, triglycerides, methyl esters of mycolic acids) are attractants, too. A mycobacterial biomass containing no lipids does not cause chemotaxis of P. aeruginosa cells.

[Effect of cyanobacteria excretions and cell biomass on hydrocarbon-oxidizing mycobacteria]. / Vliianie vydelenii i kletochnoi biomassy tsianobakterii na uglevodorodokisliaiushchie mikobakterii.

The presence of cyanobacterial cells and their exocellular excretions in an aqueous ecosystem stimulated biodegradation of diesel fuel. As was established using the technique of complete factor analysis, nitrogen addition to the medium and the presence of cyanobacterial cells in it are important for the growth of oil-oxidizing bacteria, while exocellular excretions of the cells are not sufficient for such a growth. The mycobacterial growth depended, to a certain extent, on the age of cyanobacterial cultures.