МИКРООРГАНИЗМЫ ПУСТЫННЫХ ПОЧВ И РИЗОСФЕРЫ СОЛЕУСТОЙЧИВЫХ РАСТЕНИЙ ЗОНЫ ПРИАРАЛЬЯ

Аннотация

Subject of the research: soils of deserted zones and rhizosphere of desert plants, halo- and thermotolerant bacteria Purpose of work: the main aim was search for and isolation of halotolerant and thermotolerant bacteria from salty soils of the Southern Aral Sea region, determination of their diversity and establishment of the collection of extremophilic bacteria with valuable biotechnological features. Methods of the research: classical microbiological (Yegorov, 1995; Gusev and Mineeva, 2006; Dobrovol’skaya, Skvotsova and Lysak, 1989) and biochemical (Yesikova et al., 2002; Yegorov, 2003) methods. The results achieved and their novelty: for the first time, the distribution of halo- and thermotolerant microorganisms was studied in details for specific conditions of the Ustyurt Plateau, deserts Aralkum and Karakum, which are characterized by extreme natural conditions. The frequency of their appearance in different substrates (soil, plants’ rhizosphere and so on) was determined as well. 1152 strains of halo- and thermotolerant bacteria were isolated from salty and alkali soils of the Southern Aral Sea region (Central Karakum, Aralkum and the Ustyurt Plateau). 27 extremophilic bacteria and producers Bacillus circulans 600, B. circulans 608, B. muciloginosis 334, strain Halobacteriaceae 301 were selected and identified. Optimal medium was determined and cultivation conditions were optimized for growth and development of extremophiles. Their resistance to antibiotics was studied and antagonistic activity of selected bacteria was determined. It was revealed that metabolites of extremophilic bacteria increase seeds’ germination and growth of desert plants. For the first time, the collection of indigenous halo- and thermotolerant bacteria isolated from natural zones with extreme environmental factors was established. Practical value: for the first time in Uzbekistan the detailed microbiological work on study of microbial diversity of desert and deserted biotopes of the Southern Aral Sea region and on isolation and study of halo- and thermotolerant bacteria characteristic for that region was conducted. Obtained theoretical data may be included in to study books recommended for the educational institutions. Degree of embed and economic efficiency: isolated extremophilic bacteria may be applied for rehabilitation of grazing areas of the desert regions of Uzbekistan. Field of application: fundamental and applied microbiology, biotechnology, agriculture.