Requirements of Pseudomonas aeruginosaDissociants in Glucose, Nitrate, and Phosphate. Limiting Concentrations of the Nutrients during Batch Cultivation

Requirements of R-, S-, and M-dissociants of Pseudomonas aeruginosaK-2 strain in glucose, nitrate, and phosphate, as well as the error of determination, have been calculated from the data of 250 experiments on their batch cultivation on the media with the various initial content of these resources. The resource requirements of R- and S-dissociants appear indistinguishable within the error limits. The requirements of M-dissociant significantly differ from those of R- and S-forms; however, due to specific growth of the M-form, the confidence intervals of the measured values can overlap with those of R-space and S-forms. The obtained requirement values allow an evaluation of the studied resources concentration limiting the culture growth.     

Mechanisms of the inhibition of Fe2+-induced oxidation of phosphatidylcholine by polyhydroxynaphthoquinones

The kinetics of egg phosphatidylcholine oxidation induced by an artificial prooxidant Fe2+--ascorbate system or hematine was followed by oxygen uptake. The protective effect of natural free radical scavangers--polyhydroxynaphthoquinones, ionol (BHT), alpha-tocopherol and EDTA was estimated by the decrease of the phosphatidylcholine oxidation rate. EDTA was shown to inhibit the Fe2+--ascorbate-induced oxidation but had no effect on the hematine-induced oxidation. The inhibiting effect of polyhydroxynaphthoquinones on Fe2+--ascorbate-induced oxidation was 10-100 times as high as that on hematine-induced oxidation. The effects of BHT and alpha-tocopherol were the same in both models. Natural polyhydroxynaphthoquinones interacted with the free radical diphenylpicrylhydrazyl in stoichiometric ratios coinciding with the number of beta-hydroxyls in naphthoquinone molecules; the methylation of these hydroxyls fully suppressed such an interaction. Two possible mechanisms of action of polyhydroxynaphthoquinones as antioxidative agents are discussed. The first of these is coupled with the formation of Fe2+--PHNQ complexes, while the second one--with their effect as free radical scavengers. In both cases, beta-hydroxyls of naphthoquinone molecules were shown to play a key role.     

Parameters of cardiac hemodynamics and physical development in indigenous inhabitants and caucasoids of military age born in different Northeastern Regions of Russia

Comparative analysis of the basic parameters of physical development and cardiovascular system in indigenous inhabitants and north-born Caucasoids of different northeastern regions of Russia (the Chukotka Autonomous District, Magadan oblast) has been performed. No significant differences in most of morphological and functional parameters have been found between the groups of subjects, which proves that convergent adaptation processes occur under the current social conditions in both ethnic groups regardless of the region.     

Acrylamide and Acrylic Acid Biodegradation by <Emphasis Type="Italic">Alcaligenes faecalis</Emphasis> 2 Planktonic Cells and Biofilms

The ability of the Alcaligenes faecalis 2 strain to utilize acrylamide and acrylic acid upon cultivation with these compounds as the only sources of carbon and energy has been investigated. Complete utilization of the acrylic acid present in the medium at concentrations below 0.113 g/L was observed by cultivation day 5, at a concentration of 0.225 g/L by day 7, and at a concentration of 0.45 g/L by day 17. Complete utilization of the acrylamide present in the medium at concentrations below 0.4 g/L was observed by day 5, at a concentration of 0.9 g/L by day 7, and at a concentration of 1.8 g/L by day 20. Importantly, bacterial growth did not start before complete transformation of acrylamide into acrylic acid. The rate of acrylamide transformation by growing bacteria and a cell suspension in the stationary growth phase amounted to 12.5 mg/L h at a cell concentration of 610 mg/L and 300 mg/L h, at a concentration of 1500 mg/L. A. faecalis 2 cells immobilized on BVV-22 basalt fibers and Carbopon-B-aktiv at concentrations of 3000 and 800 mg dry cells/L, respectively, transformed acrylamide at a rate of 1200 mg/L h.     

Optimization of nutrient medium for submerged cultivation of Ganoderma lucidum (Curt.: Fr.) P. Karst

The dependence of the amount of the grown vegetative mycelium of Ganoderma lucidum on the composition of the nutrient medium has been studied under conditions of submerged cultivation. The medium was optimized using full factorial and steepest ascent experimental designs. The addition of two carbon sources to the medium considerably improved the submerged growth of the fungus. An optimized medium provided for a high yield (20-20.95 g/l) of the morphologically homogeneous mycelium and shortened the cultivation period to 3-4 days.     

3-Dimensional microscopy as a method for volume measurement in cells undergoing apoptosis

Different patterns of cell volume perturbations are commonly used for modes of cell death: necrosis (cell swelling) and apoptosis (cell shrinkage). In this study we employed recently developed three dimensional microscopy for the measurement of the volume of attached vascular smooth muscle cells transfected with E1A-adenoviral protein. These cells undergo rapid apoptosis in the absence of growth factors or in the presence of staurosporine. In 30–60 min of serum deprivation the volume of these cells is increased by ～40% that corresponds to the time point of maximal activation of caspase 3 and chromatin cleavage. In 10–15 min swollen cells exhibit morphological collapse indicated by formation of apoptotic bodies. In contrast to serum-deprived cells, staurosporine leads to attenuation of cell volume by 30%. In this case, apoptotic bodies are detected in ～2.5 h after maximal shrinkage. Thus, our results show that cell shrinkage can not be considered as universal hallmark of apoptosis. The role of stimulus-specific cell volume perturbation in the triggering of the cell death machinery should be examined further.     

IR and Raman spectroscopy in the study of carotenoids of <Emphasis Type="Italic">Cladophora rivularis</Emphasis> algae

Using Raman and infrared spectroscopy it has been found that during the normal life of algae (pH changes from 8.0 to 9.0) the content of carotenoids increases and the molecules change their conformation: the contribution of–C=C–bonds of the polyene chain of a carotenoid molecule (Raman spectroscopy) is reduced and the contribution of methyl groups (～2940 cm^–1) and aromatic C–H-plane deformation vibrations (band at 1050 cm^–1) of carotenoid molecules (infrared spectroscopy) decreases as well. It is the opinion of the authors that a change in the extracellular pH within the normal range has no influence on the content of chlorophyll a and b, but tends to increase the content and alter the conformation or structure of carotenoid molecules.     

Calculation of local Hurst exponents in the Ca(2+)-activated K(+)-channel dwell time

A novel method based on the maximum overlap wavelet transform of dwell time series is proposed. Information on local multifractal properties of the series, namely local Hurst exponents or Holder exponents, was obtained. The results confirm the presence of multifractality and intrinsic correlations in the Ca(2+)-activated K+ channel dwell time series. The data on the local multifractal structure of the series can be interpreted in terms of processes having self-organized criticality. The proposed approach allows one to widen the store of methods for the analysis of single ion channel activity.