Natural selection of specific protobiomonomers during abiogenic development of the prototype genetic code is hindered by the diversity of structural, spatial, and rotational isomers that have identical elemental composition and molecular mass (M), but can vary significantly in their physicochemical characteristics, such as the melting temperature Tm, the Tm:M ratio, and the solubility in water, due to different positions of atoms in the molecule. These parameters differ between cis- and trans-isomers of dicarboxylic acids, spatial monosaccharide isomers, and structural isomers of α-, β-, and γ-amino acids. The stable planar heterocyclic molecules of the major nucleobases comprise four (C, H, N, O) or three (C, H, N) elements and contain a single –C=C bond and two nitrogen atoms in each heterocycle involved in C–N and C=N bonds. They exist as isomeric resonance hybrids of single and double bonds and as a mixture of tautomer forms due to the presence of –C=O and/or –NH2 side groups. They are thermostable, insoluble in water, and exhibit solid-state stability, which is of central importance for DNA molecules as carriers of genetic information. In M–Tm diagrams, proteinogenic amino acids and the corresponding codons are distributed fairly regularly relative to the distinct clusters of purine and pyrimidine bases, reflecting the correspondence between codons and amino acids that was established in different periods of genetic code development. The body of data on the evolution of the genetic code system indicates that the elemental composition and molecular structure of protobiomonomers, and their M, Tm, photostability, and aqueous solubility determined their selection in the emergence of the standard genetic code.

Extremophilic prokaryotes, inhabitants of hot, cold, acidic, alkaline, saline, and deep-sea ecosystems, are classified as mono- and polyextremophilic or extreme-tolerant. Under conditions of heating, acidification, or salinization, thermophilic saprotrophic archaea are capable of maintaining endogenous homeostasis and high growth rates by biosynthesis of heat shock enzymes (proteins ofgeneral stress response), C40C40 membrane tetraesters with different numbers of cyclopentane rings, trehalose, and other hyperosmolytes. Small size of reduced genomes (0.5–3.0 Mb) of archaeal thermoacidophiles and hyperthermophiles was shown to reflect their adaptability mainly due to phenotypic changes and probably to have a reduced potential for speciation. In contrast, psychrophilic heterotrophic bacteria respond to sublethal temperature decrease by increased conformational flexibility of the macromolecules and elevated content of unsaturated fatty acids in the composition of their membrane lipids, synthesize membrane-associated glycoproteins, anti-freeze proteins, a group of general stress response proteins, specific and inducible cold shock proteins, which increase the growth rate. When slowing down and stopping the growth, psychrophiles switch on the processes of secondary metabolism and sharply increasing the biosynthesis of adaptogenic exopolysaccharides. Thus, they ameliorate the direct effects of salinity and hydrostatic pressure on viable cells, block the viral attack, and affect the microstructure and physicochemical properties of ice. Marine psychrophilic and piezopsychrophilic bacteria havelarger genomes of 2.6–6.4 Mb, which reflects their adaptability due to genotypic changes and an increased potential for speciation.

Three pigmented strains of halophilic archaea (RS75, RS77, RS79) were isolated from the monoliths of mottled sylvinite from the Verkhnekamsk salt deposit (Solikamsk, Russia). The cells were nonmotile, gram-negative, pleomorphic, disk-shaped or ovoid, 0.8–1.0 × 1.5–2.5 μm. The organism was a chemoorganotrophic obligate aerobe producing catalase and oxidase. A number of carbohydrates and carboxylic acids were used as growth substrates. Growth occurred in the presence of 7–27 % NaCl (with the optimum at 15–18 %), 0.02–20 % KCl (0.2–1 %), 0.2–16 % MgCl2 (2–3 %), in the temperature range from 23 to 51 °C (40–45 °C), and pH 5.5–8.0 (6.8–7.0). The membranes contained carotenoids of the bacterioruberin series. Phosphatidylglyceromethylphosphate (PGP-Me), phosphatidylglycerol (PG), sulfated diglycosyl diether (S-DGD-1) predominated among the polar lipids. The DNA G + C content was 64.0–65.0 mol %. Phylogenetic analysis of the 16S rRNA gene sequences showed high similarity of the new strains to Haloferax species: H. denitrificans (99.2 %) and H. volcanii (99.1 %), H. larsenii (96.9 %) and H. elongans (96.6 %). DNA–DNA hybridization revealed 93–95 % similarity between strain RS75 and strains RS77 and RS79; the similarity levels between strain RS75 and the type strains of Haloferax denitrificans VKM B-1754T and Halobacterium salinarum VKM B-1769T were 50 and 10 %, respectively. According to its phenotypic and genotypic characteristics, the organism was classified as a member of the genus Haloferax, forming a new species with the proposed name Haloferax chudinovii sp. nov. type strain is RS75T (=VKPM B-11279T).

The ability of the strains-destructors of various aromatic compounds to utilize trinitrotoluene (TNT) up to concentration of 70 mg/l was shown. An increase in the TNT concentration from 100 to 150 mg/l did not inhibit its conversion rate by the Kocuria palustris RS32 strain. The Acinetobacter sp. VT11 strain utilized TNT as a sole substrate for growth; 3,5-dinitro-4-methyl anilide acetate and 2,6-dinitro-4-aminotoluene were identified as intermediates of TNT degradation by active strains of Pseudomonas sp. VT-7W and Kocuria rosea RS51. At the same time, 4-methyl-3,5-dinitroformamide was discovered for the first time upon the TNT destruction by the bacteria strains of Rhdococcus opacus 1G and Rhdococcus sp. VT-7. The active bacterial strains achieved an 82-90% destruction of TNT when they were introduced into the soil.

Три пигментированных штамма галоархей, RS94–96, изолированы из кислых пенных продуктов флотационного обогащения калийных минералов ОАО “Сильвинит” (г. Соликамск, Россия). Клетки грамотрицательные, неподвижные, плеоморфные, овоидные, размером 1.0 1.5 ? 1.5–2.5 мкм. Хемоорганотрофы, облигатные аэробы, образуют каталазу. Используют ряд углеводов и карбоновых кислот, аминокислоты и пептиды. Галофилы, термотолерантные нейтрофилы. Растут в присутствии 15–30% NaCl (оптимум 20–22%) и 0.005–0.7 М Mg2+ (0.1–0.2 М), в пределах рН 5.0–8.2 (оптимум 7.0–7.2) и 25–55°С (оптимум 35–50°С). В составе клеточных жирных кислот преобладают С16: 0, С18:1, С18:0 и С16:1. Мембраны содержат каротиноидные пигменты бактериорубериновой серии и полярные липиды, представленные преимущественно С20,С20 изопреноидными дериватами: фосфатидилглицерометилфосфат, фосфатидилглицерин и три неидентифицированных сульфатированных гликолипида типа S-DGD. Содержание Г + Ц в ДНК составляет 65.1–66.4 мол. %. Согласно филогенетическому анализу данных секвенирования гена 16S pДНК термотолерантный нейтрофильный изолят RS94 (Г + Ц в ДНК – 66.4 мол. %.) наиболее близок к непигментированному умеренному ацидофилу Halarchaeum acidiphilum MH1-52-1T (97.3%). По фенотипическим и генотипическим признакам, изученный организм описан в качестве нового вида рода Halarchaeum с предлагаемым названием Halarchaeum solikamskense sp. nov. Типовой штамм RS94Т (= ВКПМ В-11282Т).

A halophilic nonpigmented rod-shaped (0.8–1.0 × 2.0–2.5 μm), gram-negative bacterium with a single polar flagellum (strain RS91) was isolated from acidic brines of flotation enrichment of potassium minerals (Silvinit Co., Solikamsk, Russia). The strain grew in the media with 2 to 25% NaCl (optimum at 10–12%), 20–45°C (optimum at 37°C), and pH 5.5–8.5 (optimum 6.5–7.5). It was an aerobe or facultative anaerobe incapable of fermentation. The strain was characterized by the absence of growth on glucose, fructose, and citrate, extensive aerobic growth on n -hexadecane and in the mineral medium with H 2 + O 2 + CO 2 in the gas phase, anaerobic nitrate reduction with acetate or hydrogen (under H 2 + CO 2 + N 2 ), and variable fatty acid composition. The DNA G+C content was 68.2 mol %. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that while strain RS91 was most closely related to Arhodomonas aquaeolei HA-1 T (98.3%) and Nitrococcus mobilis (98.1%), it was only remotely related to the halophilic phototroph Halorhodospira halophila (90.6%). Based on the combination of its phenotypic and genotypic characteristics, the organism was classified as a new species of the genus Arhodomonas , family Ectothiorhodospiraceae with the proposed name Arhodomonas recens sp. nov. The type strain is RS91 T (= IEGM 796 T = VKPM B-11280 T ).

Three pigmented strains of halophilic archaea, RS94-RS96, were isolated from acidic foamy products of flotation enrichment of potassium minerals (Silvinit Co., Solikamsk, Russia). The cells were gram-negative, nonmotile, pleomorphic ovoids, 1.0−1.5 × 1.5−2.5 μm. The isolates were chemoorganotrophic, obligately aerobic, and catalase-positive. A range of carbohydrates and organic acids was used, as well as amino acids and peptides. The strains were halophiles and thermotolerant neutrophiles. They grew in the media with 15 to 30% NaCl (optimum at 20–22%) and 0.005–0.7 M Mg 2+ (0.1–0.2 M), at pH 5.0–8.2 (optimum 7.0–7.2) and 25–55°C (optimum at 35–50°C). The major fatty acids were C 16:0 , C 18:1 , C 18:0 , and C 16:1 . The membranes contained carotenoid pigments of the bacterioruberin series and polar lipids, mostly as C 20 ,C 20 isoprenoid derivates: phosphatidylglyceromethylphosphate, phosphatidylglycerol, and three unidentified sulfated glycolipids of the S-DGD type. The DNA G+C content was 65.1–66.4 mol %. Phylogenetic analysis based on the 16S rRNA gene sequencing revealed that the thermotolerant neutrophilic isolate RS94 (DNA G+C content of 66.4 mol %) was most closely related to the nonpigmented moderate acidophile Halarchaeum acidiphilum MH1-52-1 T (97.3%). Based on its phenotypic and genotypic characteristics, the organism was classified as a new species of the genus Halarchaeum with the proposed name Halarchaeum solikamskense sp. nov. The type strain is RS94 T (= VKPM B-11282 T ).

Показана способность штаммов-деструкторов различных ароматических соединений утилизировать тринитротолуол (ТНТ) в концентрации до 70 мг/л. Увеличение концентрации ТНТ от 100 до 150 мг/л не ингибировало скорость конверсии этого соединения штаммом Kocuria palustris RS32. Штамм Acinetobacter sp. VT11 использовал ТНТ в качестве единственного субстрата для роста. Среди интермедиатов деградации ТНТ активными штаммами Pseudomonas sp. VT-7W и Kocuria rosea RS51 идентифицированы 3,5-динитро-4-метил-анилид уксусной кислоты и 2,6-динитро-4-аминотолуол. При деструкции ТНТ штаммами бактерий Rhodococcus opacus 1G и Rhodococcus sp. VT-7 впервые обнаружен 4-метил-3,5-динитроформамид. Активные бактериальные штаммы при интродукции в почву осуществляли разложение ТНТ на 82–90%.

Based on the results of IR-spectroscopic and gas-chromatographic analysis, the release and absorption of methane on the modification of Kizelovsk brown coal, Barzas sapromixite, and Balkhash alginite was considered. The dispersion of strong bulk aggregates of brown coal to particles of size 0.1–1.2 mm resulted in the release of methane; the process was enhanced as the temperature was increased from −35 to 200°C. Brown coal particles became incapable of generating CH 4 and intensely chemisorbed it as the coal matter became alkylated and esterified by methanol vapor at 67°C. This transition occurred under mild conditions in a laboratory experiment without the use of special catalysts at comparatively small CH 3 OH additives to brown coal (no more than 1.5 ml/g). Brittle particles of flag barzassite and rubberlike balkhashite did not generate methane; however, they changed from initially slow physical adsorption of CH 4 in native particles to intense chemisorption upon interaction with methanol at 67°C (to 0.3 ml of CH 3 OH per gram of balkhashite and to 1.2 ml per gram of barzassite)

The results of studies on molecular nitrogen fixation and denitrification by plankton, epiphytone, and epilithone in a number of natural and anthropogenic waterways of the Kama River Basin are presented for summer and autumn periods of 2005. The nitrogen fixation and denitrification was quantified by acetylene gas chromatography. The phototrophic anoxybiotic purple non-sulfurous bacteria, in particular, of Rhodopseudomonas, Rhodobacter and Rhodocyclus genera, play a significant role in active denitrification in the presence of sulfide-free flow water in the Kama River and its inflows in epilithone, algal-bacterial mats, and biological sewage disposal plants in Perm. On the other hand, the heterocyst cyanobacteria of Anabaena and Aphanizomenon genera had a leading position in active N-2 fixation in the plankton and periphyton of the lower river streams.

AIM:To detect the integron-positive strains among nosocomial Acinetobacter spp. and to determine their relationship on the genotype level.MATERIALS AND METHODS:Amplification by polymerase chain reaction using primers specific to sequences of the class 1 and 2 intergrons on the genomic DNA template followed by restriction fragments length polymorphism analysis as well as RAPD-genotyping of the integron-positive strains were performed.RESULTS:Fact of spreading of Acinetobacter baumanii strain containing class 1 integron in medical centers was established. The composition of the integron's gene cassettes was analogous to worldwide (including epidemic) types.CONCLUSION:Molecular genetic analysis of the mobilized structures (integrons) under the standardization of used approaches are suitable for the surveillance for circulation of epidemic strains of nosocomial pathogens.

Bacteria of the genus Pseudomonas, isolated from the water of the lakes Shira and Itkul (Republic of Khakassia, Russia) were shown to contain integrons of class 1 with gene cassettes, contained in the variable segment (sized 1 and 1.3 kb), were shown. Out of three detected integrons only one integron (in P. aeruginosa) included the sulfanilamide resistance gene contained in the 3'-conservative segment. The resistance of bacteria to kanamycin and ceftazidime was not seemingly linked with the presence of integrons. On the whole, the study revealed the presence of a significant proportion (27%) of integron-positive strains among aquatic bacteria with pronounced resistance to antibiotics.

The genotype structure and silver sulfadiazine (SDS) resistance of a number of Acinetobacter baumanii strains that circulated for a prolonged period of time in burn UCUs were studied. The most resistant strain (SDS MIC 50 mcg/ml) contained a class 1 integron with the gene of sulfonamides resistance (sul1) in its genome. Possible reasons for selection of the multiple resistance among Acinetobacter spp. in burn units are discussed.

The total population density and the biomass of bacterioplankton, mesozooplankton, and phosphate-accumulating bacteria (PAB) were estimated during the 2000–2001 summer–autumn seasons in the coastal waters of the White and Barents Seas, which are subject to the action of tidal and sea currents, the inflow of riverine waters, and anthropogenic impact. In the shallow estuarine waters with salinities of 6.5–32‰ near the Chernaya, Pesha, and Pechora River mouths, the population of PAB fluctuated from 0.1 to 9.1 million cells/ml (0–36% of the total bacterial population). In pelagic seawaters, which are low in phosphates (12–50 μg/l) and are characterized by an increased iron/phosphorus ratio (2.0–3.6), bacterioplankton amounted to 0.1–1.6 million cells/ml and was mainly represented by small organisms with a volume of 0.08–0.15 μm3, commonly lacking intracellular polyphosphates. In the pelagic zone of the Barents Sea, the biomass of mesozooplankton (Bz) was comparable with that of bacterioplankton (Bb = 39–175 mg/m3), the Bb/Bz ratio being 1.4–4.6. Off the Varandeiskii, Pechora, and Kolguyev oil terminals, Bb increased to 155–300 mg/m3 and the Bb/Bz ratio rose to 1.4 to 50.3 (with an average value of 20.9), presumably due to the severe anthropogenic impact on these waters. In this case, the dense population of bacterioplankton (0.9–7.6 million cells/ml) was mainly represented by large cells (0.12–0.76 μm3 in volume), most of which (3–43% of the total bacterioplankton population) contained polyphosphates. The chemical composition of these waters was characterized by an elevated content of the total phosphorus (65–128 μg/l) and by a low iron/phosphorus ratio (0.9–1.2).

The formation of polyhydroxyalkanoates granules in anaerobically grown Escherichia coliM-17 cells was found to be preceded by the intracellular accumulation of carbonic acids (predominantly, acetic acid), amounting to 9% of the cytosol. The intracellular concentration of acidic metabolites increased after the lyophilization of the bacterial biomass and decreased after its long-term storage (3.5–13.5 years). The decrease in the concentration of acidic metabolites is likely due to the dehydration of dimeric carbonic acids in the viscoelastic cytosol of resting bacterial cells. The hydrophobic obligately aerobic cells of Acinetobacter calcoaceticusIEGM 549 are able to utilize a wide range of growth substrates (from acetate and citrate to hydrophobic hydrocarbons), which is considerably wider than the range of the growth substrates of E. coli(predominantly, carbohydrates). The minimal essential and optimal concentrations of orthophosphates in the growth medium of A. calcoaceticuswere found to be tens of times lower than in the case of E. coli.The intracellular content of orthophosphates in A. calcoaceticuscells reached 35–77% of the total phosphorus content (Ptotal), providing for the intense synthesis of polyphosphates. The Ptotalof the A. calcoaceticuscells grown in media with different proportions between the concentrations of acetate and phosphorus varied from 0.7 to 3.3%, averaging 2%. This value of Ptotalis about two times higher than that observed for fermenting E. colicells. Lowering the cultivation temperature of A. calcoaceticusfrom 37–32 to 4°C augmented the accumulation of orthophosphates in the cytoplasm, presumably owing to a decreased requirement of growth processes for orthophosphate. In this case, if the concentration of phosphates in the cultivation medium was low, they were completely depleted.

The effect of various factors on the activity and biosynthesis of nitrogenase in Clostridium butyricum was estimated by the rate of acetylene reduction at different growth phases in the static culture. The activity of nitrogenase was found to be low in vegetative cells; it increased and reached the maximum at the stage of prospore formation and decreased in the course of sporulation. The duration of different stages in the cell growth cycle depended on temperature and the composition of the medium. An increase in the rate of nitrogenase synthesis at the stage of prospore formation was favoured by the presence of sodium acetate or yeast autolysate in the medium; ammonium chloride inhibited the mechanism of nitrogenase biosynthesis. Cytoplasmic membranous structures such as tubular-vesicular or lamellar mesosomes were formed in active nitrogen fixing cells grown in a medium with yeast autolysat. Such structures were absent from cells with a low activity grown in a medium containing ammonium chloride.

The rate of molecular nitrogen fixation was determined in bottom grounds of three Estonian lakes and the Rybinsk water reservoir in the summer of 1977--1978. Certain species of nitrogen fixing bacteria were found to be confined to lakes of certain trophic type. Ecological niches with the mass growth of Clostridium pasteurianum, Azomonas agilis and Clostridium butyricum were detected in the sediments of eutrophic lakes. Ecological niches of Az. insignis and Cl. acetobutylicum occur in polyhumic lakes. Ecological niches for the nitrogen fixing microaerophilic organisms Methylosinus trichosporium, M. sporium and Mycobacterium flavum can be found in the sediments of water reservoirs of any trophic type. The important ecological factors which favour the growth of microflora with a high rate of molecular nitrogen fixation in bottom grounds are as follows: a sufficiently high temperature, a weakly alkaline reaction, the presence of oxygen in the water near the bottom, and the ratio of organic carbon to total nitrogen about 10--11. The destruction of organic substances in such sediments involves both aerobic and anaerobic microflora, and Cl. butyricum is abundant among nitrogen fixing microorganisms.

A method of gas chromatography is described for determining the rate of microbial methane oxidation. In the Rybinskoye Reservoir, the rate of methane oxidation in the microaerobic zone of water layers near the bottom over the silted former channel of the Mologa River was found to be 51.1 to 86.2 mcl of CH4 per litre per day at 2--3 degrees C, constituting 8--16% of the original methane content.

The rate of production and mineralization of organic matter and the rate of fixation of molecular nitrogen were assayed in th eutrophic lake Beloye (near Moscow) at the end of summer stagnation (1976). The content of hydrogen sulphide reached 6.8 mg per litre which resulted in a change of the ecological environment in the lake. The fixation of molecular nitrogen in water layers was characterized by three maxima: 5.0 mcg N per litre per 4 hours (surface); 4.2 mcg N per litre per 4 hours (metalimnion) and 2.8 mcg N per litre per 4 hours (at bottom). The fixation of nitrogen in the trophogenous layer involved mainly the blue-green alga Anabaena. In the sulphide zone, molecular nitrogen was fixed by butyric and sulphate-reducing bacteria.