The evolution of the early precambrian geobiological systems

Bacterial paleontology provides vast opportunities for the study of all types of sedimentary and volcanic-sedimentary rocks, at any stage of metamorphism and of any age. Bacteria are shown to play an important role in weathering, transfer, sedimentation, and diagenesis of the sediments and in the formation of many minerals that have previously been thought to be abiogenic.     

Hemolytic activity of hybrid antioxidants Ichphans

The hemolytic activity of new spatially hindered hybrid antioxidants—Ichphans—has been studied. The concentration-dependent hemolytic action of high concentrations of Ichphans with 8, 10, 12, or 16 carbon atoms in the aliphatic chain has been revealed. A nonmonotonic dependence of the hemolytic activity on the hydrophobic properties of Ichphans has been found.     

Periodicities in nucleotide distribution in the immunoglobulin light chain locus of Gallus gallus

Fourier spectra of nucleotide sequences from chicken (Gallus gallus) chromosome 15 were obtained. Periodical structures of several fragments of the Ig light chain locus were characterized. The Fourier spectra of the locus and its parts (variable and constant segments, enhancer, and sequences supposedly associated with somatic hypermutation) were shown to be unique among those of other chromosome 15 fragments.     

Improvement of arachidonic acid and eicosapentaenoic acid production by increasing the copy number of the genes encoding fatty acid desaturase and elongase into <Emphasis Type="Italic">Pichia pastoris</Emphasis>

Genes encoding Δ6 desaturase, Δ6 fatty acid elongase, and Δ5 desaturase from the alga, Phaeodactylum tricornutum, were co-expressed in Pichia pastoris to produce arachidonic acid (ARA; 20:4 Δ^{5, 8, 11, 14}) and eicosapentaenoic acid (EPA; 20:5 Δ^{5, 8, 11, 14, 17}). A panel of Pichia clones carrying progressively increasing copies of the heterologous gene expression cassette was created using an in vitro multimerization approach. ARA and EPA accumulated up to 0.3 and 0.1% of total fatty acids, respectively, in the recombinant P. pastoris carrying with double copies of these three heterologous genes, as compared to 0.1 and 0.05%, respectively, in the recombinant P. pastoris with single copy. Yun-Tao Li and Mao-Teng Li contributed equally to this work.     

Inhibition of lung metastasis in mice by intravascular injection of dendritic cells and natural killer cells

To investigate the efficacy of dendritic cells and natural killer cells in the inhibition of lung metastasis, we injected dendritic cells and natural killer cells intravascularly into mice bearing B16F10 tumour melanoma cells. This efficiently inhibited tumor growth and prolonged survival. In addition, surviving mice developed a long-lasting memory response against the original tumor when re-challenged with live tumor cells. Intravenous administration of dendritic cells and natural killer cells may be a potential way to treat lung metastasis in patients.     

The Extracellular Protein of Luteococcus japonicus subsp. casei Reactivates Cells Inactivated by UV Irradiation or Heat Shock

The culture liquid of Luteococcus japonicus subsp. casei was found to be able to reactivate cells of this bacterium inactivated by UV irradiation or heat shock. The antistress activity of the culture liquid was due to the presence of an extracellular exometabolite of a protein nature with a molecular mass of more than 10 kDa. When the bacterium was grown in a nutrient broth or glucose-containing mineral medium, the antistress protein was secreted by cells in the logarithmic growth phase. The reactivating effect of the antistress protein was inversely proportional to the survival rate of stressed cells.     

A Catecholic Siderophore Produced by the Thermoresistant Bacillus licheniformis VK21 Strain

Thermophilic and thermoresistant strains of bacilli were screened on a medium containing Chrome Azurol S for the producers of siderophores. It was found that the Bacillus licheniformis VK21 strain dramatically increases secretion of the metabolite, a chelator of Fe³⁺, in response to addition of manganese(II) salts. The growth of the producer on a minimal medium containing MnSO₄ under the conditions of iron deficiency is accompanied by the accumulation of a catecholic product, the content of which reaches maximum at the beginning of the stationary growth phase of culture. In the presence of FeCl₃, the amount of the catecholic product in the medium considerably decreases. The siderophore, called S_VK21, was isolated from the cultural medium and purified by reversed phase HPLC, and its siderophore function was confirmed by the test for the restoration of growth of producer cells in a medium containing EDTA. The UV spectrum of the siderophore has absorption maxima at 248 and 315 nm. According to the amino acid analysis and NMR spectrometry, the metabolite S_VK21 is 2,3-dihydroxybenzoyl-glycyl-threonine.