Characteristics of the Microflora of Saline Soils of Armenia

Recultivation of saline lands is one of the most urgent problems of agriculture in the Republic of Armenia. The biotechnological methods, in particular the use of biological fertilizers on the base of osmotolerant nitrogen-fixing microorganisms resistant to high concentrations of NaCl, play an important role at the present stage of land restoration. The purpose of this work was to isolate halophilic bacteria from the saline lands of some regions of Armenia, to study and characterize these bacteria, and then to create effective biofertilizer on their basis that promotes recultivation of saline areas. The salt composition of soil samples taken from the saline lands of the villages of Mrgashat, Yeghegnut, Gai (Armavir region), Ranchpar, Sis and Sipanik (Ararat region) was studied during the project. In samples, both the total titer of microorganisms and the titre of nitrogen-fixing bacteria were determined in the respective selective media. Twenty five pure cultures of bacteria were isolated from the samples, and their morphological-physiological and biochemical properties, as well as their nitrogen-fixing activity were studied. As a result, we selected eight cultures with relatively high nitrogen-fixing activity, as well as with resistance to various environmental factors, in particular, to high NaCl concentrations, alkaline pH values and to sharp temperature changes. After an appropriate phylogenetic analysis, the selected cultures can become a potential object for the creation of an integrated biological fertilizer that will promote the restoration of arid and saline lands and the increase of their fertility.

soil, salinity, degradation, halopilic bacteria, nitrogen-fixation, biofertilizer, recultivation

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