شناسایی مولکولی و بیوشیمیایی باکتری‌های پروبیوتیک ریزوسفر گیاه Helianthemum ledifolium و خاک دنبلان بیابانی (Terfezia claveryi) در استان گلستان

Today, among edible fungi desert truffles are very important for human health. The occurrence of ecological changes in the environmental equilibrium caused their reduction in nature. During this study sampling was followed by collecting samples of rhizosphere region of Helianthemum ledifolium and desert truffle surrounding soils in Golestan province. Seven strains of gram-positive Lactobacillus and negative catalase which isolated and identified on MRS agar medium. Biochemical tests showed some of the strains were able to grow in acidic condition from 3 to 8. and they were able to tolerate up to 8% salt. Strains also had the ability to grow at minimum 15 0C and maximum 45 0C. In the carbohydrate fermentation test, all 7 strains showed similar profiles in the fermentation of glucose, fructose, lactose, sucrose, arabinose and galactose. On the other hand, none of these strains could lead to fermentation of xylose sugar. Using the 16S rDNA gene sequence, the molecular identification of strains belonging to the different strains of L. plantarum which were detected, L. plantarum strain R11, R12, R21, R22, R31, S11 and S12. The strains were registered on the NCBI site with numbers MG841152 to MG841158. The antifungal effects of bacterial isolates against fungi of Fusarium solani, Verticillium dahliae and after-harvesting agents of Aspergillus niger and Penicillium expansum in MRS agar medium by doual culture method showed that the maximum growth inhibitory for P. expansum and F. solani were 69.37 and 66.69 percent, respectively. Sporulation reduced in P. expansum in comparison to the control. The results showed that lactic acid bacteria with plant and soil origin could inhibit the growth of fungi and bacteria with high spectrum and can be used as safe probiotic bacteria in post harvest crop contamination.