Diatoms significantly differ from other groups of heterokont algae in the diversity of chloroplast forms, their number, and location in a cell and in the structure of pyrenoids. The information on the fine structure of chloroplast is recognized to be important for taxonomic and phylogenetic studies of diatoms. Six species of diatoms belonging to different classes have been examined using transmission electron microscopy.
View Article and Find Full Text PDFIzv Akad Nauk Ser Biol
December 2008
The results of studies on the phytoplankton of Southern Baikal in 2004 show that siliceous stomatocysts (cysts) of chrysophyte algae make a significant contribution to this community. Their abundance reaches a peak of 46 800 cysts/l between August and October, when the concentration of biogenic elements is minimum. The D/C coefficient (the ratio of diatom cells to cysts) varies during the year, reflecting the seasonal succession of phytoplankton and changes in the concentration of biogenic elements in the photic layer.
View Article and Find Full Text PDFTwo cyanobacterial strains, Pseudanabaena sp. 0411 and Synechococcus sp. 0431, were isolated from a sample collected in the Kotel'nikovskii hot spring of the Baikal rift.
View Article and Find Full Text PDFMol Gen Mikrobiol Virusol
September 2006
Deletions are very important sources of the variability among members of the mycobacterial tuberculosis complex (MTC). Deletion analysis of MTC clinical isolates was performed to clarify phylogenetic relationships and help to identify epidemiologically significant groups of the MTC. In this study, the variability of the TbDl, RD6 and pks15/1 chromosome loci in clinical MTC strains and comparison of those results with IS6110-RFLP (restriction fragment length polymorphism), sSNP (synonymous single nucleotide polymorphism), PGG (Principal Genetic Group) typing data were used to determine if these chromosome regions constitute good molecular markers for some of the epidemiologically important groups of the MTC.
View Article and Find Full Text PDFPolysaccharide composition of neutral, acid- and alkali-soluble fractions of the diatoms Stephanodiscus meyerii Genkal et Popovsk and Aulacoseira baicalensis (K. Meyer) Simonsen of Lake Baikal has been studied. Neutral polysaccharides were represented by chrysolaminarans (1-->3;1-->6-beta-D-glucans).
View Article and Find Full Text PDFSequencing of fragments of genes coding for silicic acid transport (SIT) proteins of diatoms of evolutionary distant classes (centric Chaetoceros muelleri Lemmermann, pennate araphid Synedra acus Kützing, pennate raphid Phaeodactylum tricornutum Bohlin, and pennate with keeled raphe system Cylindrotheca fusiformis Reimann et Lewin), revealed the presence in these proteins of a conservative amino acid motif CMLD. Hydropathy profiles suggest that CMLD occupies a position between two transmembrane strands which do not contain lysine and arginine residues. The two strands are good candidates for the role of the channel along which transport of silicic acid occurs.
View Article and Find Full Text PDFThe chromatin organization of E. coli cells, taken on various growth stages of the culture (active, stationary, grown with heightened density), displays different characters when examined by the Miller method. In the active phase of growth, the cell chromatin is released as threads and loops of DNA, threads of nucleosome-like particles and granules 25-38 nm in size.
View Article and Find Full Text PDFAntiviral activity of RNA-ase isolated from the fermentation broth of Actinomyces rimosus was studied. The effect of the enzyme on multiplication of the viruses of vesicular stomatitis, Newcastle and cariolovaccine diseases was investigated. It was found that the enzyme was capable of suppressing reproduction of the vesicular stomatitis virus (VSV) in the culture of chick fibroblast cells.
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