sp. nov., isolated from a thawing ancient ice wedge.

A novel actinobacterium, strain K3-2, was isolated in pure culture from a thawing ancient ice wedge at Mammoth Mountain (Eastern Siberia, Russia). Colonies of strain K3-2 were yellowish orange; cells had the fine structure typical of Gram-positive bacteria, were non-motile short rods and were non-spore-forming. Strain K3-2 was mesophilic (optimum growth at 28 °С), but capable of growing at 4 °С.

Prokaryotic community in Pleistocene ice wedges of Mammoth Mountain.

Ice wedges differ from other types of surface and underground glacial bodies and are widely spread in perennially frozen sub-Arctic regions, but the bacterial and archaeal diversity in these permafrost features remains poorly studied. Here, we compared the prokaryotic community composition in the active layer and ancient, 13-19 kyr BP and ~ 40 kyr BP, ice wedge horizons from the same exposure profile of the Mammoth Mountain, using pyrosequencing 16S rRNA gene. The most abundant OTUs in the active layer were affiliated with Acidobacteria (31.

[Effect of Distant Interactions on Growth and Development of Streptomycetes].

Regulation of streptomycete growth and development by distant interactions of physical nature was shown using a vial-in-vial experimental setup, providing physical isolation of the inducer and detector cultures. Some effects of distant interaction were observed with Streptomyces netropsis proliferating submerged culture as an inducer and a surface culture of the same strain as a detector. The growth rate of the detector strain doubled.

[Diversity of bacterial forms in ice wedge of the Mamontova Gora Glacial complex (central Yakutiya)].

Electron microscopic investigation of four samples of ancient ice wedge from the Pleistocene glacial complex of Mamontova Gora (Yakutiya, Russia) revealed high diversity of bacteriomorphic particles. Their structural features included the presence of electron-transparent zones, presumably inclusions containing storage compounds, and microenvironment (capsules or external sheaths). These features may be a result of adaptive strategies providing for microbial survival under permafrost conditions.

[Structural organization of the phospholipid constituent of cell membranes from Streptomyces hygroscopicus, as determined from neutron diffraction data].

The nanoparameters of the membrane from actinobacteria have been determined by the method of neutron diffraction on multilamellar lipid membranes. It was found that the repeat distance of a partly hydrated membrane formed from the phosphohpid fraction of Streptomyces hygroscopicus (S. hygroscopicus) is 85.

[Non-species-specific effects of unacylated homoserine lactone and hexylresorcinol, low molecular weight autoregulators, on the growth and development of bacteria].

We conducted a comparative study of the effects of alpha-amino-gamma-butyrolactone, the common structural element of extracellular microbial regulators of the homoserine lactone (HSL) group, and of 4-n-hexylresorcinol, an autoregulator of the alkylhydroxybenzene (AHB) group, on the growth and development of gram-positive and gram-negative bacteria. We revealed non-species-specific effects of HSL and AHB and characterized their concentration dependencies. The addition of 10(-5)-10(-3) M HSL or 10(-5)-10(-4) M AHB during the exponential growth phase of the cultures grown on balanced media resulted in cell division arrest and accelerated the transition to the stationary phase that culminated in endospore formation in Bacillus cereus, Alicyclobacillus tolerans, and Sulfobacillus thermosulfidooxidans.

[Coliphages inactivation using chitosan derivatives].

The effect of chitosan fragments with different degrees of polymerization and the chemical derivatives of chitosan differing in the number of amino groups and total molecule charge on phages T2, T4, and T7 was studied. The interaction of chitosan with bacteriophage particles inactivated them to the extent dependent on the chemical properties of chitosan and its concentration. Phage T2 was found to be most susceptible to inactivation by chitosan.

Characterization of bean mild mosaic virus: particle morphology, composition and RNA cell-free translation.

Virions of bean mild mosaic virus (BMMV) are built of 180 subunits of a single protein species of MW 40 x 10(3) [coat protein CP], packed into a T = 3 surface lattice. The capsomers on the five-fold symmetry axes protrude 2-3 nm from the particle surface. The virions encapsidate genome-size [approximately 4,200 nucleotides (nt)] as well as some heterogeneous RNAs of subgenomic size approximately 1,000-2,000 nt.