[The effect of pH, aeration, and temperature on arachidonic acid synthesis by Mortierella alpina].

The effects of pH, aeration, and temperature on the growth of fungal strain Mortierella alpina LPM-301 and the synthesis of lipids and arachidonic acid in glycerol-containing medium were studied. Arachidonic acid production in the stationary growth phase was found to depend considerably on the pH value; it reached the optimum at pH 6.0 and was irreversibly inhibited at a pH of 3.0. The PO2 values in a range from 10 to 50% showed no marked effect on mycelium growth or the synthesis of lipids and arachidonic acid. The temperature optimum for arachidonic acid production was 20-22 degrees C. Under continuous cultivation, the amount of arachidonic acid reached 29.8% of lipids and 7.4% of biomass. The arachidonic acid yield from the glycerol consumed was 4.1% by mass and 8.8% by energy. It is suggested that arachidonic acid synthesis at an unfavorable pH and elevated temperatures was limited by the activity of A-12-desaturase and by the conversion of linoleic to arachidonic acid, respectively.

Gender difference in calcification diseases: is it the result of gender-specific ways of nano-bacterial expansion?

Gender difference has been reported for frequency of the calcification diseases in urogenital system: according to published statistics data, they are more numerous in males. We suggest that the male increasing is due to nanobacterial infections and ways of their dissemination. There are specific gender-dependent ways for these infections which bring infection to the different target organs, namely: urinary tract, kidney, prostate in men and placenta in women. Identification of the suggested microbial pathogens and investigation of sex-determined pathways for the dissemination are the following steps to get ascertaining events of gender reasons for different calcification diseases.

[Biosynthesis of arachidonic acid by micromycetes (review)].

Arachidonic acid (ARA, 5,8,11,14-cis-eicosatetraenoic acid) is widely used in medicine, pharmaceutics, cosmetics, dietary nutrition, agriculture, and other fields. Microbiological production of ARA is of increased interest since the natural sources (pig liver, adrenal glands, and egg-yolk) cannot satisfy its growing requirements. Mechanisms for ARA biosynthesis as well as the regulation of enzymes involved in this process are considered. Review summarizes literature data concerning individual stages of microbiological ARA production, methods for screening of active strains-producers, physiological regulation of ARA synthesis in micromycetes (the effect of growth phase, medium composition, pH, temperature, and aeration), and effective technologies of fermentation and the product recovery. Information on the whole biotechnological process from strain selection to the ARA yield improvement and purification of the end product is presented.

Desulfosporosinus hippei sp. nov., a mesophilic sulfate-reducing bacterium isolated from permafrost.

The sulfate-reducing strain 343T was isolated from ancient permafrost deposits in Siberia, Russia. Based on 16S rRNA gene sequence analyses, this strain was closely related to Desulfosporosinus species, showing 97.9 % 16S rRNA gene sequence similarity to Desulfosporosinus meridiei DSM 13257T, 97.6 % similarity to Desulfosporosinus auripigmenti DSM 13351T, 97.2 % similarity to Desulfosporosinus lacus DSM 15449T and 96.2 % similarity to Desulfosporosinus orientis DSM 765T. The strain was found to contain b-type cytochromes and to reduce only sulfate and thiosulfate using lactate as an electron donor but not sulfite, elemental sulfur, fumarate, nitrate or Fe(III). These data, considered in conjunction with DNA-DNA hybridization data, cell-wall chemotaxonomy and data on physiology, support recognition of strain 343T as representing a distinct and novel species within the genus Desulfosporosinus, namely Desulfosporosinus hippei sp. nov., with the type strain 343T (=DSM 8344T =VKM B-2003T).

EDTA-dependent assimilation of glucose and organic acids by an EDTA-degrading bacterium.

Bacterial strain VKM B-2445 is characterized by ethylenediaminetetraacetate (EDTA) requirement for cell growth. This strain could not grow on glucose and organic acids as the sole sources of carbon and energy, but it was able to metabolize these substrates added to EDTA medium. EDTA initiated assimilation of glucose, succinate, fumarate, malate, and citrate and supplied nitrogen for the biomass production from these substrates. Utilization of primarily nongrowth substrates by strain VKM B-2445 started when EDTA was exhausted or at least considerably degraded.

[Ultrastructural organization and development cycle of soil ultramicrobacteria belonging to the class Alphaproteobacteria].

Gram-negative chemoorganotrophic soil ultramicrobacteria (UMB), strains NF1 and NF3, have been isolated. In their development cycle, the strains formed small coccoid cells of 400-800 nm and ultrasmall cells of 200-300 nm. Phylogenetically, the strains NF1 and NF3 belong to Alphaproteobacteria and are close to the type strain of the recently described species Kaistia adipata. The ultrastructure of UMB cells has been studied using ultrathin sections and freeze-fracturing. It has been shown that the structure of UMB cell walls is of the gram-negative type; the outer membrane and peptidoglycan layer are well differentiated. The cell surface has numerous protrusions (prosthecae) of conical or spherical shape filled with the contents of the periplasm. The formation of unusual cellular structures (not occurring in known free-living bacteria) is a feature of UMB: these include the following: (a) piles of rod-like subunits, ca. 30 A in diameter and 150-250 angstroms in length: (b) long bunches (up to 300-400 angstroms) comprised of filamentous subunits; and (c) large electron-dense spherical bodies (up to 200-300 angstroms in diameter) localized in the periplasm. A distinctive feature of UMB is their ability to grow as facultative parasites on living cyanobacterial (CB) cells. In this case, three types of interaction between UMB and CB have been revealed: (1) adsorption of UMB cells on the surface of CB cells; (2) penetration of UMB into polysaccharide sheathes; and (3) penetration of UMB into CB eytoplasm. UMB cells have been shown to reproduce by budding, with buds (up to 2-3) located directly on the mother cell, without formation of intennediate hyphae.

Link between the early calcium deposition in placenta and nanobacterial-like infection.

The placenta is a vitally important organ in the regulation of embryonic development. That is why extensive calcium deposition [also named as pathological placental calcification (PPC)] could have serious negative consequences for the adequate growth of embryos. The nature and mechanism of PPC development has not been defined as yet. In the present investigation, we have tested the hypothesis that the molecular basis of PPC development consists of nanobacteria-induced calcification in infected female placenta. Electron microscopy findings support this hypothesis. The initial stage of micro-calcification may originate from the external surface of individual nanobacteria-like particles found mainly in placental extracellular matrix, where initial calcium deposition occurs as a needle surface deposition or as an amorphous-like surface precipitate. Further calcific propagation in placenta takes place in the newly formed macro-cavities, which are characterized by low electron density, possibly reflecting its liquid content around calcium deposition. The micro-cavities contain free nanobacterial-like particles, which may relate to atypical Gram-negative bacteria but not to apoptotic bodies by morphological characters and DNA/RNA distribution. We hypothesize that the increased placental calcification might be caused, at least in part, by nanobacterial infection.

[Corrosion of pipe steel samples and conjugated conversion of sulfur compounds by thiobacteria Halothiobacillus neapolitanus DSM 15147].

The kinetics of conversion of sulfur compounds by Halothiobacillus neapolitanus DSM 15147 bacteria was studied in the presence of steel samples. It was shown that the presence of steel altered the known pathway of sulfur compound oxidation by thiobacteria. Production of atomic hydrogen via the interaction between biogenic sulfuric acid and steel enhanced secondary production of intermediates and decreased the content of sulfate produced previously. The process was accompanied by pH elevation and continuation of intense growth of the thiobacterium culture. Thiobacteria formed a corrosive medium, which caused metal destruction. The protective properties of anticorrosive coatings 225 LS and 640 mk were tested. It was shown that these coatings protected steel from the destructive effect of biogenic sulfuric acid.

Anaerobic co-reduction of chromate and nitrate by bacterial cultures of Staphylococcus epidermidis L-02.

Industrial wastewater is often polluted by Cr(VI) compounds, presenting a serious environmental problem. This study addresses the removal of toxic, mutagenic Cr(VI) by means of microbial reduction to Cr(III), which can then be precipitated as oxides or hydroxides and extracted from the aquatic system. A strain of Staphylococcus epidermidis L-02 was isolated from a bacterial consortium used for the remediation of a chromate-contaminated constructed wetland system. This strain reduced Cr(VI) by using pyruvate as an electron donor under anaerobic conditions. The aims of the present study were to investigate the specific rate of Cr(VI) reduction by the strain L-02, the effects of chromate and nitrate (available as electron acceptors) on the strain, and the interference of chromate and nitrate reduction processes. The presence of Cr(VI) decreased the growth rate of the bacterium. Chromate and nitrate reduction did not occur under sterile conditions but was observed during tests with the strain L-02. The presence of nitrate increased both the specific Cr(VI) reduction rate and the cell number. Under denitrifying conditions, Cr(VI) reduction was not inhibited by nitrite, which was produced during nitrate reduction. The average specific rate of chromate reduction reached 4.4 micromol Cr 10(10 )cells(-1 )h(-1), but was only 2.0 micromol Cr 10(10 )cells(-1 )h(-1) at 20 degrees C. The maximum specific rate was as high as 8.8-9.8 micromol Cr 10(10 )cells(-1 )h(-1). The role of nitrate in chromate reduction is discussed.

Model experiments on the microbial removal of chromium from contaminated groundwater.

A bacterial consortium with representatives of sulfate-reducing and denitrifying bacteria was selectively enriched. Model experiments under microaerobic conditions showed that it precipitated chromium from Cr (VI)-containing waters (area of a former electroplating factory, Leipzig, Germany) by two different mechanisms: by sulfate reduction and precipitation as sulfide, and by some direct reduction. Sulfate reduction needed fatty acids as organic substrates and resulted at the first stage in no sulfide accumulation. In the absence of the fatty acids but with straw as organic substrate, the direct reduction of chromium was observed without sulfate reduction. In this case Cr (VI)-reduction rate correlated with that of the denitrification.

New magnet-sensitive structures in bacterial and archaeal cells.

The objects of the investigation were: distribution of intracellular magnet-sensitive structures among different taxonomic groups of prokaryotes, localisation and organisation of the magnet-sensitive inclusions (MsI) in cells. The MsI were discovered in representatives of both prokaryotic domains (Bacteria and Archaea), 2 kingdoms and 7 orders of bacteria. They were some amorphous or non-crystalline globules with the electron-transparent centre surrounded with an electron-dense homogenous matrix. The magnetic nature of the structures was shown by attraction with an applied magnet both for the cell suspensions and for the MsI isolated and separated from the destroyed cells. The MsI were studied with transparent electron microscopy and with X-ray analyses. When the cells were grown in the iron-containing nutrient medium, the matrix was enriched with iron. It was shown also that some bacteria grown with cobalt or with chromium contained the cobalt- or chromium-enriched magnetic inclusions.

[Methane production by the sulfate-reducing bacterium Desulfosarcina variabilis]. / Obrazovanie metana cul'fatvosstanavlivaiushchei bakterii Desulfosarcina variabilis.

The sulfate-reducing bacterium Desulfosarcina variabilis VKM B-1694 was found to produce up to 1.62 mumol methane per mg protein when grown on different substrates. The role of methanogenesis and the physicochemical factors determining this process in sulfate-reducing bacteria are discussed.

[About nannobacteria]. / O nannobakteriiakh.

Bacterial nanocells 0.2-0.3 micron in size and hundreds of a cubic micron in volume have been revealed in natural habitats and obtained in pure cultures. The taxonomic analysis of naturally occurring nanobacteria showed that they belong to the known taxa of the kingdom Eubacteria. The results of the cytological investigation of nanocells suggest that they are universally formed in response to stress impacts.

Hypnotic effect of i.v. thiopentone is enhanced by i.m. administration of either lignocaine or bupivacaine.

We have compared the hypnotic requirements for i.v. thiopentone alone and in combination with i.m. lignocaine or bupivacaine. Ninety women, ASA I-II, undergoing minor gynaecological surgery were allocated randomly to nine groups of 10 patients to receive thiopentone combined with i.m. lignocaine, bupivacaine or saline, respectively. Thiopentone was administered in bolus doses of 0.5 mg kg-1 every 30 s until loss of response to verbal command. Lignocaine and bupivacaine significantly enhanced the hypnotic effect of thiopentone in a dose-dependent manner. The maximum doses tested (lignocaine 3.0 mg kg-1 and bupivacaine 1.0 mg kg-1) reduced the hypnotic dose of thiopentone by 39% and 48%, respectively. We conclude that if lignocaine or bupivacaine are injected into soft tissue before induction of anaesthesia by thiopentone, the i.v. dose of the latter should be modified accordingly.

Removal of H2S by the purple sulphur bacterium Ectothiorhodospira shaposhnikovii.

When Ectothiorhodospira shaposhnikovii VKM B-1525 was used for desuphurization of biogas in the laboratory and in a pilot plant, there was complete oxidation of H2S, the main product being elemental sulphur. The advatage of this culture over green bacteria is discussed.

[Effect of hyperbaric oxygenation on the corticosterone content of the blood in experimental acute respiratory distress syndrome]. / Vliianie giperbaricheskoi oksigenatsii na soderzhanie kortikosterone v krovi pri ostrom respiratornom distress-sindrome v éksperimente.

The three series of experiments conducted on 139 adult wistar rats it was found, that two-hour stay of the animals in barochamber under the pressure of 3 atmospheres reduces considerably the percentage of mortality rate and decelerates the development of arterial hypoxemia in rats with an experimental model of acute respiratory distress syndrome (ARDS) reproduced by intrapleural injection of oleic acid (0.27 ml/100 g). Stalle in comparison with the control (I) series elevation of corticosterone in the animal blood II and III series (conduction of HBO correspondingly in 4 and 12 hours from the beginning of the process) is considered as the manifestation of one of the most important mechanism of organism adaptation to the development of acute hypoxia in ARDS.

[Effect of the oxidation-reduction potential of the medium on the production of gentamycin]. / Vliianie okislitel'no-vosstanovitel'nogo potentsiala sredy na obrazovanie gentamitsina.

The medium redox potential had an effect on gentamicin production by Micromonospora purpurea v. violacea, strain VNIIA 7R. The Eh influence was shown to be statistically reliable when the results were expressed in relative units against the control. In the laboratory experiments with low volumes of the medium the Eh increase by more than 170 per cent induced inhibition of gentamicin biosynthesis while the Eh increase by 108 to 168 per cent induced stimulation of the activity.