[Bacterioplankton of the Kola Bay, Barents Sea, (micro- and nanoforms) based on 2002-2003 monitoring data].

Hydrochemical and microbiological investigation in the Kola Bay in 2002-2003 demonstrated that the distribution of bacteria is notably influenced by biogeochemical barriers formed by mixing fresh and sea water. Seasonal changes in the appearance of filterable bacteria, considerable quantities of gram-positive bacteria with thick cell walls, dwarf bacteria, spheroplasts, elementary bodies, and cells with abnormal cell walls during the polar night have been revealed. Cultured bacterial colonies were represented by polymorphic cells. The data obtained refine our knowledge about organotrophic activity of bacterioplankton during the polar night.

[Nanobiology of the ocean]. / Nanobiologiia okeana.

The concepts of nanobiotic forms and their relationships with oceanic organic matter and feeding as well as their role in oceanic communities are proposed on the basis of long-term electron microscopy and microbiological studies initiated in 1969 in the Barents Sea, Atlantic and Pacific oceans, and marginal seas of the Arctic Ocean.

Antibacterial activity of seawater and microvibrion-predators (Microvibrio marinus Roscoffensis) in it.

In the seawater of the Atlantic Ocean and surface waters of different points of the World Ocean, including arctic basins and equatorial regions, microvibrion-predators of bacterial cells have been discovered. The number of microvibrions in the surface waters of the English Channel reaches a thousand cells per ml, but it varies, depending on the season. In this article a method of the separation and culture of microvibrions is described. The ultrastructure of two strains of microvibrions was investigated and a similarity found between their structure and Gram-negative bacteria. The distinctive features of microvibrions are their sea derivation and the ability to reproduce only in the presence of bacteria, without penetrating bacterial cells. To a certain extent, the antibacterial activity of seawater is connected with the presence in it of microvibrions.

Some problems of the ecology and taxonomy of marine microvibrios.

The bactericidal effect of water from the Indian and Pacific oceans and Caspian and White seas on Escherichia coli was studied. It is shown that a decrease in the viability of E. coli cells is accompanied by the appearance and active multiplication of small bacteria of a vibrioid form. Two strains of such bacteria were isolated from a suspension of E. coli in seawater and purified from membranes of the substrate organism by the method of centrifugation in a Ficoll gradient. The marine bacteria of vibrioid form are very similar to the bacterial parasite Bdellovibrio bacteriovorus in fatty acid composition and characteristic cycle of development.