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101.
Streshinskaya G. M. Kozlova Yu. I. Shashkov A. S. Evtushenko L. I. Naumova I. B. 《Microbiology》2003,72(4):455-460
The cell wall anionic polymers of the 13 species of the Streptomyces cyaneus cluster have a similar structure and contain -glucosylated 1,5-poly(ribitol phosphate) and 1,3-poly(glycerol phosphate). In the degree of glucosylation of the ribitol phosphate units of their teichoic acids, the cluster members can be divided into two groups. The streptomycetes of the first group (S. afghaniensis, S. janthinus, S. purpurascens, S. roseoviolaceus, and S. violatus) are characterized by a very similar structure of their cell walls, the completely glucosylated 1,5-poly(ribitol phosphate) chains, and a high degree of DNA homology (67–88% according to literature data). The cell wall teichoic acids of the second group (S. azureus, S. bellus, S. caelestis, S. coeruleorubidus, S. curacoi, and S. violarus) differ in the degree of -glucosylation of their 1,5-poly(ribitol phosphate) chains and have a lower level of DNA homology (54–76% according to literature data). Two streptomycetes of the cluster (S. cyaneus and S. hawaiiensis) are genetically distant from the other cluster members but have the same composition and structure of the cell wall teichoic acids as the second-group streptomycetes. The data obtained confirm the genetic relatedness of the S. cyaneus cluster members and suggest that the structure of the cell wall teichoic acids may serve as one of the taxonomic criteria of the species-level status of streptomycetes. 相似文献
102.
Aleksakhina NN Basnak'ian IA Kozlova NN 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(5):71-75
Experimental data giving grounds for the development of a new group C meningococcal whole-culture preparation for oral administration are presented. The study revealed that the use of the controlled cultivation of group C meningococci and a nutrient medium with definite chemical composition in combination with the "soft" method of the isolation of the whole-culture preparation ensured the preservation of polysaccharide, outer membrane protein and lipooligosaccharide in a native state, as well as retaining their full antigenic value, in the preparation. The oral immunization with the whole-culture preparation stimulated the multiple elevation of the level of hemagglutinating and IgG antibodies to these antigens and their prolonged preservation in the blood of immunized animals. 相似文献
103.
Aleksakhina NN Basnak'ian IA Kozlova NN Verner IK 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(4):35-40
The whole-culture vaccine preparation of Neisseria meningitidis, serogroup B, obtained by cultivation in a computer-controlled bioreactor, was studied. The preparation was shown to contain antigenically active polysaccharide, outer membrane proteins, as well as lipooligosaccharide, faintly pyrogenic and with low toxicity. After oral immunization of rabbits a multiple increase in the levels of IgG antibodies to these antigens in their blood serum was noted during the period of observation (303 days). 相似文献
104.
Suzina NE Muliukin AL Kozlova AN Shorokhova AP Dmitriev VV Barinova ES Mokhova ON El'-Registan GI Duda VI 《Mikrobiologiia》2004,73(4):516-529
Using electron microscopy (ultrathin sections and freeze-fractures), we investigated the ultrastructure of the resting cells formed in the cultures of Micrococcus luteus, Arthrobacter globiformis, and Pseudomonas aurantiaca under conditions of prolonged incubation (up to 9 months). These resting cells included cyst-like forms that were characterized by complex cell structure and the following ultrastructural properties: (i) a thickened or multiprofiled cell wall (CW), typically made up of a layer of the preexisting CW and one to three de novo synthesized murein layers; (ii) a thick, structurally differentiated capsule; (iii) presence of large intramembrane particles (d = 180-270 A), occurring both on the PF and EF sides of the membrane fractures of M. luteus and A. globiformis; (iv) a peculiar structure of the cytoplasm, which was either fine-grained or lumpy (coarse-grained) in different parts of the cell population; and (v) a condensed nucleoid. Intense formation of cyst-like cells occurred in aged (2- to 9-month-old) bacterial cultures grown on diluted complex media or on nitrogen-, carbon-, and phosphorus-limited synthetic media, as well as in suspensions of cells incubated in media with sodium silicate. The general morphological properties, ultrastructural organization, and physiological features of cyst-like cells formed during the developmental cycle suggest that constitutive dormancy is characteristic of non-spore-forming bacteria. 相似文献
105.
Kozlova OV Egorov SIu Kupriianova-Ashina FG Read N El'-Registan GI 《Mikrobiologiia》2004,73(6):734-740
Using the mutant strain Aspergillus awamori 66A producing a recombinant Ca2+-dependent photosensitive protein aequorin, the dynamics of Ca2+ was studied for the first time in the cytosol of the micromycetes exposed to stressful factors, such as an increase in extracellular Ca2+ to 50 mM, hypoosmotic shock, and mechanical shock. Cell response to stress proved to involve an increase in the Ca2+ concentration in the cytosol, which was determined from the amplitude of aequorin luminescence and the time of the amplitude enhancement and relaxation. The level of Ca2+ response depended on the physiological stimulus. Inhibitory analysis with various agents that block Ca2+ channels and with agonists that specifically enhance the activity of the channels suggested that (1) the level of Ca2+ in the cytosol of micromycetes increases in response to stress because of the ion influx from both the growth medium and intracellular reservoirs and (2) the potential-dependent transport systems play the major role in the Ca2+ influx into the cytosol of the micromycete cells. 相似文献
106.
O. V. Kozlova S. Yu. Egorov F. G. Kupriyanova-Ashina Nick Rid G. I. El’-Registan 《Microbiology》2004,73(6):629-634
Using the mutant strain Aspergillus awamori 66A, producing the recombinant Ca2+-dependent photosensitive protein aequorin, the dynamics of Ca2+ was studied for the first time in the cytosol of micromycetes exposed to stressful factors, such as an increase in extracellular Ca2+ to 50 mM, hypoosmotic shock, and mechanical shock. The cell response to stress proved to involve an increase in the Ca2+ concentration in the cytosol, which was determined from the amplitude of aequorin luminescence and the time of the amplitude enhancement and relaxation. The level of the Ca2+ response depended on the physiological stimulus. Inhibitory analysis with various agents that block Ca2+ channels and with agonists that specifically enhance the activity of the channels suggested that (1) the level of Ca2+ in the cytosol of micromycetes increases in response to stress because of the ion influx from both the growth medium and intracellular reservoirs and (2) potential-dependent transport systems play the major role in the Ca2+ influx into the cytosol of the micromycete cells.Translated from Mikrobiologiya, Vol. 73, No. 6, 2004, pp. 734–740.Original Russian Text Copyright © 2004 by Kozlova, Egorov, Kupriyanova-Ashina, Rid, El-Registan. 相似文献
107.
Yaroslavov AA Kuchenkova OY Okuneva IB Melik-Nubarov NS Kozlova NO Lobyshev VI Menger FM Kabanov VA 《Biochimica et biophysica acta》2003,1611(1-2):44-54
Small (40-60 nm in diameter) and large (300-350 nm) negative vesicles were complexed with a cationic polypeptide, poly-L-lysine (PL). Laser microelectrophoresis experiments showed that in small vesicles rendered anionic with the addition of cardiolipin (CL(2-)), only the CL(2-) in the outer leaflet is involved in the complexation with PL. Calorimetric and other data demonstrate that the binding of PL to the membrane surface causes domains ("rafts") of CL(2-) to form in the outer leaflet, and it is these domains that electrostatically bind the polymer. The kinetics of transmembrane permeation of doxorubicin (Dox, a fluorescent anti-tumor drug) was monitored with and without PL binding to the outer surface of the vesicles. It was found that PL mediates the permeation of Dox into the vesicle interior. In the absence of PL, the Dox molecule (possessing an amino group of pK(a)=8.6) binds to the anionic vesicles in the protonated form and, consequently, suffers an impaired mobility through the membrane. On the other hand, when the PL covers the vesicle surface, Dox passes though the membrane with greater ease. The effects of salt and polyanion on the stability of PL-vesicle complexes and the PL-mediated Dox permeation are also discussed. 相似文献
108.
Babenko OV Saakian SV Brovkina AF Kozlova VM Strel'nikov VV Zaletaev DV Nemtsova MV 《Molekuliarnaia biologiia》2002,36(4):623-629
The spectrum and frequencies of RB1 structural defects were studied in tumors and peripheral blood lymphocytes of patients with various forms of retinoblastoma. Single strand conformation polymorphism (SSCP) and heteroduplex (HA) analyses, along with direct sequencing, revealed 47 mutations, including 24 new ones. Of these, 42.5% were nonsense mutations, 15% were missense mutations, 15% affected splicing sites, and 27.5% were frameshifts resulting from microdeletions or microinsertions. Six polymorphisms were found, including three new ones located in the coding region. Microsatellite analysis with markers Rbint2, Rbint20, D13S262, and D13S284 revealed a loss of heterozygosity for at least one marker in 71% tumors. 相似文献
109.
AV. H. HEWOOD EDITAE 《Botanical journal of the Linnean Society. Linnean Society of London》1979,78(3):235-236
Following the publication of the last of the series of Flora Europaea Notulae, No. 20 in the Botanical Journal of the Linnean Society , 76: 297–384 (1978), a number of additions or alterations have been drawn to our attention. These are published in continuation. 相似文献
110.
Mitochondrial ultrastructure in roots of mesophyte and hydrophyte at anoxia and after glucose feeding 总被引:1,自引:1,他引:0
Summary In order to investigate the nature of the tolerance of mesophytes and hydrophytes to root anaerobiosis, changes in the mitochondrial ultrastructure of excised roots (with and without added glucose under anoxia) were studied in plants from two ecologically opposite types-pumpkin and rice.A 12-hour exposure to anoxia led to mitochondrial degradation in roots of adult rice and pumpkin plants. The addition of glucose preserved cell ultrastructure for up to 72–96 hours. During this period mitochondrial ultrastructure changed. In rice roots this primarily involved an increased number of cristae and a change in their arrangement into parallel rows. Cells of pumpkin roots displayed long mitochondria (up to 55 m) of different profiles which fused to form a complex mitochondrial network that was in close association with parts of the endoplasmic reticulum carrying a large number of ribosomes. This may be regarded as an adaptive development that facilitates the transport of glycolytic energy along mitochondrial membranes to the sites of protein synthesis.It is concluded that root cells of a hydrophyte are not more tolerant to anoxia than mesophyte. Thus, the ability of hydrophytes to grow on anaerobic soils should be attributed not so much to peculiar features of the roots' metabolism but to the ability of these plants to perform an easy transport of O2 from leaves to roots. With respect to mesophytes it is stressed that the supply of assimilates is important for the resistance of roots to soil anaerobiosis. 相似文献