Dose-dependent effects  of  sodium   nitrate (NaNO3) on  the  dynamic of  neurological disorders after  brain   ischemia induced  by  bilateral   occlussion  of  common  carotid artery   were investigated in  rats  of Wistar  line.  NaNO3  at  50 and  500  mg/1000 g decreased the  death-rate and  neurological disorders. NaNO3  at  5 mg/1000 g had  no  effect.

Symbiosis  has  been  considered as  a  biological basis  of  infectious process.   Particular attention was  paid  to  the  change of  paradigm in  symbiology   and  the  appearance of  a  novel  term  — associative   symbiosis.   Principal  structural-and-functional  elements  of  associative  symbiosis   were   estimated, and  3  vectors  of  infectious process  such  as  1)  host  — normaflora, 2)  host  — associants, 3)  associants — indigious   microflora (microsymbiocenosis) were  isolated. Functions  of  microsymbionts   that   determine  colonization  resistance  of  the   host,   and   the   formation  of  dysbioses   and pathobiocenoses were  reviewed.  Defensiability of biotopes of an  organism against  microbes is connected with  substrates  overcoming  of  which,   associants with  persistent potential  carry  out.   Basis of  interaction of  symbionts makes   up  the  change of  persistent potential  and  antagonism both   of an  infectious causative   agent  and  of  commensal microorganisms. Material was  presented to  characterize the  role  of  intercellular interactions  of  symbionts at  the  level  of  prokaryotes, proeukaryotes  under  conditions of infectious pathology.

Melafen stimulating effect on cell growth of cyanobacteria Synechococcus 6301 amounted to 30—45% at 1000 lux cultures illumination. Cells illumination in the area saturation (4000 lux) produced to decrease of melafen action. Growth rate and biomass accumulation of Anabaena variabilis cells made up 20—25% lower with nitrogen then without one in the medium. Melafen more efficiently stimulated cultures growth rate without nitrogen. Data indicate melafen activates photosynthetic processes and quite possible atmospheric nitrogen fixation in the cells. Heavy me­tal Cd²⁺ ions decreased biomass accumulation and average number cells in the filaments of A. va­riabilis. Melafen took away partially Cd²+ toxical effect. Cu²+ ions depressed Synechococcus 6301 and Chlorella vulgaris cells growth, but stimulated carbohydrate accumulation. Cu²+ ions action was partially decreased by melafen. It is supposed that melafen shows untistress activity in the conditions of toxic heavy metal effect on the growth of phototrophic microorganisms.

It was carry out a comparative analysis of the nucleotide sequences of the rpoB gene to assess its use as a genetic marker for identification genus Lactobacillus spp., obtained from acid milk product of different regions of Kazakhstan. Discriminatory ability of the nucleotide sequence analyze of rpoB gene is higher than the 16S rRNA gene for closely related species of the Lactoba­cillus genus. Phylogeny of nucleotide sequence of rpoB gene is identical to 16S rRNA gene and can be used as its additional phylogenetic marker.

The reactivity of the exometabolites allocated in the culture liquid in cultures of actinomy- cetes, cyanobacteria and microalgae as possible using like the ecophysiological criterion of the selection of partners for the create mixed cultures and associative pairs of microorganisms has been considered.

The combined effect of Cd, Co and Cu to phytoplankton marine in situ experiment was in­vestigated using the full factorial design. The samples were taken before of heavy metal and 1, 3, 5 and 7 days after for to count up of cell number. It was found that various species differ signi­ficantly in their response the action heavy metal and their mixture. During exposition reduction of species diversity occurred and population density of most abundant algae decreased. The effect of heavy metal on the decrease of species number and structure of phytoplankton community was also estimated.

The flora of a cave Akshtyrskaya, developing in conditions of artificial lighting is inves­tigated. The quantitative count of the area of an overgrowing is conducted the taxonomic ana­lysis of views. The formed communities are described and the predominant views are detached. The correlation between taxonomic structure of epibioses and geology-mineralogical properties of substrates was shown.

The influence of periodic cut and tread of the meadows, lawns and heterogeneous bio- coenosis on structure ant communities of Moscow city was investigated. From seven Moscow species living on open sites, are sensitive even to small treading Formica cunicularia, Myrmica gallienii and M. schencki. Lasius umbratus lives on periodically cut sites, transferring their nests entirely to the ground. However it does not endure treading. M. rubra maintains weak treading and machining of lawns. M. rugulosa and L. niger are the steadiest against recreational loadings. The abundance of the last even increases.