Eshaghi Ebrahim, Nosrati Rahim, Owlia Parviz, Malboobi Mohammad Ali, Ghaseminejad Pejman, Ganjali Mohammad Reza
Department of Biology, Nourdanesh Institute of Higher Education, Meymeh, Isfahan, Iran.
Cellular and Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Iran J Microbiol. 2019 Oct;11(5):419-430.
Iron and zinc are two essential micro-nutrients for plant growth and development. Therefore, isolation of siderophores-producing and zinc-solubilizing rhizobacteria involved in bio-availability of these elements is of great interest.
In this study, soil samples collected from slightly alkaline soil types were screened for high levels of siderophore secretion and zinc solubilization.
Among positive colonies, three isolates, named F21A, F37 and F38, were able to secrete siderophore at high levels, ranged between 200 and 300 μM/liter. A close association was observed between siderophore production capability and growth rate as an indicator of active metabolism. Siderophore production was closely correlated with the level of zinc ion released into the medium as well. All three siderophore producing isolates were able to withstand temperature as high as 37°C, high concentration of NaCl (up to 2.5%) and a wide range of initial pH from 6 to 9 while hydrolyzing Zn compounds actively. One of the isolates, F21A, tolerated the presence of 200 mgl of zinc. Biochemical and molecular characteristics are indicative that these isolates are . As experienced in a greenhouse experiment, inoculation with the F21A and F37 isolates significantly increase the plants height, fresh and dry weight of corn with compared to control.
These findings demonstrated that the potential of strains as plants growth promoting rhizobacteria (PGPR) in iron and zinc deficient soils.
铁和锌是植物生长发育所必需的两种微量营养素。因此，分离参与这些元素生物有效性的产铁载体和锌溶解根际细菌备受关注。
在本研究中，对从微碱性土壤类型中采集的土壤样本进行了高水平铁载体分泌和锌溶解筛选。
在阳性菌落中，三个分离株，命名为F21A、F37和F38，能够高水平分泌铁载体，范围在200至300微摩尔/升之间。观察到铁载体生产能力与作为活跃代谢指标的生长速率之间存在密切关联。铁载体生产也与释放到培养基中的锌离子水平密切相关。所有三个产铁载体分离株都能够承受高达37°C的温度、高浓度的NaCl（高达2.5%）以及6至9的广泛初始pH值，同时积极水解锌化合物。其中一个分离株F21A能够耐受200毫克/升的锌。生化和分子特征表明这些分离株是……。正如在温室实验中所经历的，与对照相比，接种F21A和F37分离株显著增加了玉米的株高、鲜重和干重。
这些发现证明了这些菌株在铁和锌缺乏土壤中作为植物促生根际细菌（PGPR）的潜力。
