عزل وتعريف وكفاءة البكتيريا المذيبة للفوسفات في بعض ترب الجبل الأخضر- ليبيا

Abstract

The experiment was conducted by preparing samples by taking forest soil as well as agricultural soil from different depths of the Al-Safsaf agricultural area. After that, laboratory analyzes of the soil are carried out, and the aim of the current study is to study the isolation, identification and efficiency of phosphate-dissolving bacteria in some soils of Al-Jabal Al-Akhdar - Libya. The results showed that the deeper the soil in forest and agricultural soils, the greater its moisture content. The depth (+10 cm) recorded the highest moisture content, while the depth (0-2.5 cm) recorded the lowest soil moisture content. It is clear from the results that agricultural soil has a higher moisture content than forest soil. The results also showed that the texture of the willow soil (forests) was clayey, containing (55%) clay, while the texture of the willow soil (agricultural) was also clayey, containing (47%) clay. It was noted that the willow soil (forests) outperformed the Willow soil (agricultural) in its clay content. It is clear from the results of some chemical properties of forest soil and agricultural soil of the Al-Safsaf agricultural station at different depths (0-2.5, 2.5-5.5-10, +10 cm) for the two types of soil studied, the results showed that as the depth of the soil increased (+10 cm) taken for estimation, some ions increased, such as calcium, magnesium, chloride, and bicarbonate, while nitrogen, phosphorus, organic matter, electrical conductivity, and pH recorded the highest values in the surface layer, in soil. Forests, as well as in agricultural soil. As the depth of the soil increases (+10 cm), the values of some ions increase, such as calcium, magnesium, chloride, pH, While bicarbonate, nitrogen, phosphorus, organic matter, and electrical conductivity recorded the highest values. The results also showed that forest soil was superior to agricultural soil in its content of chloride, bicarbonate, organic matter, and pH, while agricultural soil was superior to forest soil in calcium, magnesium, nitrogen, phosphorus, and electrical conductivity, respectively. On the other hand, the results of some morphological tests (cell shape, Gram stain, colony shape, colony texture, colony height) for the bacterial isolates obtained for the genera Bacillus and Pseudomonas showed that the cell shape was bacillary for both genera of bacteria. Bacillus bacteria were Gram positive.While Pseudomonas was Gram negative, the shape of the colony was irregular and its texture smooth and transparent for Bacillus bacteria, while the shape of the colony was circular and its texture was opaque for Pseudomonas bacteria, while the height of the colony was small for Bacillus bacteria and flat for Pseudomonas bacteria. The results also showed that the Bacillus genus was positive (+) for the tests for oxidase, urea production, indole production, gelatin liquefaction, starch hydrolysis, and nitrate reduction, and negative with the catalase test, while the Pseudomonas genus was positive (+) for the catalase oxidase, gelatin liquefaction, starch hydrolysis, and nitrate reduction tests, and was negative for urea production. and indole production, respectively. Pseudomonas bacteria recorded the highest bacterial numbers, outperforming the genus Bacillus, in forest and agricultural soils. Superphosphate fertilizer treatment showed that Bacillus bacteria recorded the highest values, respectively, after two days, two weeks, and three weeks of incubation under pH values (4.3, 5.5, 4.0), followed by Pseudomonas bacteria after two days and three weeks of incubation under pH values (4.3, 4.3). , compared to the control treatment after two and three weeks of incubation period under pH values (7.2, 4.7). In the phosphate rock treatment, Bacillus bacteria recorded the highest values, respectively, after two days and three weeks of incubation under pH values (4.0, 6.1), followed by Pseudomonas bacteria after two days and three weeks of incubation under pH values (4.4, 4.7), compared to the control treatment after Two days of incubation period under pH values (5.7). In the soil treatment, Bacillus bacteria recorded the highest values after two and three weeks, respectively, of the incubation period under pH values (7.7, 8.0), followed by Pseudomonas bacteria after two days of incubation under pH values (6.4), compared to the control treatment after two days of incubation period under pH values (6.9).