The Astrakhan region is the main vegetable-growing and melon-growing center of Russia, characterized by favorable agro–climatic conditions for growing vegetable and gourd crops. The agro-climatic conditions of the region make it possible to obtain the earliest, highest and most stable yields. Currently, in the southern regions, the problem of reducing the use of mineral fertilizers and pesticides in agriculture with their replacement by biological methods of plant protection is quite acute. Biological methods, in comparison with chemical means of protection, are distinguished by the selectivity of impact and by the environmental safety. Preliminary studies have shown that the studied laboratory sample of the agent based on Bacillus atrophaeus B‐11474 has pronounced fungistatic and growth-stimulating activities, which were confirmed by the field research results. The studied laboratory sample of the agent had a positive effect on the germination, development and biometric parameters of watermelon. The sample helped to increase productivity, reduce anthracnose, improve the qualitative and quantitative indicators of the cultivated crop. The prospects for using the triple treatment (spraying the bottom of the furrow and double spillage under the root of the plant with a laboratory sample of the agent have been established. In general, the use of a biological agent in the cultivation of watermelon in the fields of the Astrakhan region will make it possible to obtain environmentally friendly and safe products.

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In the conditions of a model laboratory experiment the influence of lead salts (an acetate and nitrate) on morphological and physiological parameters of filamentous cyanobacteria was studied. During the experiment we estimated features of formation of biomass, structure of trichomes, form and the size of cells, content of chlorophyll a, carotenoids and phycobiliproteins. It is noted that in the presence of lead acetate of up to 5 maximum allowable concentrations there is a formation of a biomass in the form of attached and free films, and presence of a nitrate form of lead at the same concentration promotes formation of filaments, fixed from one side. At the same time, the increase of concentration of both acetate, and nitrate forms of lead promotes formation of rarefied films of one layer multidirectional trichomes; to disintegration of trichomes on the fragments and separate cells united by an external mucilaginous envelope. Content of lead acetate in concentration of 15 times the maximum allowable concentration, and lead nitrate at 10 times the maximum allowable concentration leads to formation of abnormally long cells up to 10.0–10.5 µm long. It is established that lead acetate has a stimulating effect on formation of a biomass and synthesis of photosynthetic pigments. The biomass growth of up to 223.7% of the control was observed at concentration up to 15 times the maximum allowable concentration inclusive. The content of chlorophyll a grew by 30.6%, carotenoids – by 24.0% at one maximum allowable concentration. Lead nitrate stimulates a biomass gain much more weakly – up to 70.0% at 5 times the maximum allowable concentration and also has the expressed inhibiting effect on synthesis of photosynthetic pigments. Depression of concentration of chlorophyll a and carotenoids by 38.8% and 79.4% respectively was observed already at one maximum allowable concentration. The stimulating effect of lead acetate is noted on synthesis of phycocyanin (by 94.0%) and allophycocyanin (by 120.0%) in concentration up to 5 times the maximum allowable concentration; the stimulating effect of lead nitrate was observed on synthesis of phycocyanin (by 64.7%) in concentration up to 5 times the maximum allowable concentration and on synthesis of allophycocyanin (up to 140.0%) and on phycoerythrin (up to 228.0%) at concentration up to 10 times the maximum allowable concentration. Comparison of influence of various lead salts on filamentous cyanobacteria revealed a more expressed inhibiting effect of the nitrate form of lead in comparison with acetate.

The assessment of the quality of sea water samples was carried out according to biological indicators - the total number of microorganisms, which react sharply to changes in their environment. To ensure control over the ecological state of the aquatic environment, it is necessary to conduct regular monitoring studies on such microbiological indicators as the total number of microorganisms. Conventional microbiological methods for determining the total number of microorganisms are laborious and require a well-equipped laboratory and qualified personnel, and such analysis usually takes 24-48 hours. For a comparative assessment of the quality of sea water samples, the number of microorganisms was recorded by traditional methods and by the express method of chemiluminescence. As traditional methods, the method of inoculation on nutrient media, counting on a fluorescent microscope and on colored membrane filters were chosen. A chemiluminescent method was chosen for the rapid assessment of water by the total microbial abundance, which makes it possible to measure the content of bacterial cells by their ATP content. It is shown that the chemiluminescent method is superior to traditional methods for determining the total bacterial contamination (TBC, one of the main indicators of the natural object quality). At the same time, the chemiluminescent reaction made it possible to significantly reduce the measurement time and speed up data processing (measurement time did not exceed 2.5 min), i.e., it became possible to quickly analyze the samples under study in the field and in mobile laboratories. Direct positive correlations between the data determined by the traditional and new methods are revealed. The results obtained in the framework of a study on the determination of the number of microorganisms by classical methods and the chemiluminescence method allow us to recommend their use for express assessment of the quality of various natural objects.

In article prospects of use of microbic technologies in oil-extracting and a petroleum-refining industry are considered. The data about allocation forming bacterium slime from the petropolluted objects located in territory of the Astrakhan region is cited.Ключевые слова: нефтяное загрязнение, нефтеотдача, экзополисахариды бактерий, микробные технологии