Zinc-solubilizing bacteria (ZSB) are potential and ideal substitutes for Zn supplement. Currently, limited reports are available on the bacteria displaying capability to transform insoluble forms of zinc (Zn) to an available form. Therefore, attempts were made to identify and characterize Zn-solubilizing strains from chickpea rhizosphere for growth promotion and Zn biofortification. Sixty-one bacteria isolated from rhizosphere of chickpea from different parts of Indo-Gangetic plains (IGP) of India were screened for Zn-solubilizing capabilities by cultivating on BTG medium supplemented with ZnO, Zn₃(PO₄)₂, and ZnCO₃. Two potential ZSB (BT3 and CT8) were chosen based on their zinc solubilization index and zinc solubilization efficiency and later identified by 16S rRNA gene sequence analysis. In vitro assays were performed to determine their plant growth-promoting attributes. PCR assay was performed to confirm the presence of zinc uptake regulator (zur) gene in potential strains. Pot experiments were carried out to evaluate the effect of two potential ZSB (BT3 and CT8) on growth promotion and Zn biofortification in chickpea. Atomic absorption spectroscopy was employed to determine the Zn content in the plants. Out of twenty-four ZSB, only two strains (BT3 and CT8) were able to solubilize all the three Zn sources. Isolate, BT3 released maximum concentration of Zn from ZnCO₃ (150.2 ± 1.1 mg l⁻¹), while CT8 released maximum from ZnO (130.2 ± 1.2 mg l⁻¹) and Zn₃(PO₄)₂ (116.5 ± 1.2 mg l⁻¹), respectively. The pH of medium was strongly acidic which ranged from 5.2 to 3.9, and the organic acid analysis revealed hexanoic acid, pentanoic acid, and mandelic acids as prime organic acids produced by isolates. The presence of zur genes indicated the involvement of zur-mediated molecular mechanisms in these strains. These isolates also showed plant growth-promoting traits such as production of indole acetic acid (IAA), ammonia, siderophores, and phosphate solubilization. The 16S rRNA sequence analysis revealed that both the isolates had close similarity with Bacillus altitudinis. Inoculation of isolates BT3 and CT8 improved the growth parameters of chickpea and increased the plant’s Zn uptake by 3.9–6.0%. B. altitudinis strains (BT3 and CT8) show excellent capabilities to solubilize insoluble Zn compounds like oxides, phosphates, and carbonates of Zn, making them valuable source for improving Zn uptake and growth of chickpea.

增锌细菌（ZSB）是补充锌的潜在和理想的替代品。目前，关于细菌展示将不溶形式的锌（Zn）转化为可用形式的能力的报道很少。因此，人们试图从鹰嘴豆根际中鉴定和鉴定增锌菌株，以促进生长和锌的生物强化。通过在补充了ZnO，Zn ₃（PO ₄）₂和ZnCO _3的BTG培养基上进行培养，从印度鹰嘴平原（IGP）不同地区的鹰嘴豆根际分离出的61种细菌具有锌增溶能力。。根据锌的增溶指数和锌的增溶效率，选择了两个潜在的ZSB（BT3和CT8），然后通过16S rRNA基因序列分析进行鉴定。进行体外测定以确定它们促进植物生长的特性。进行PCR测定以确认潜在菌株中锌摄取调节剂（zur）基因的存在。进行盆栽实验以评估两种潜在的ZSB（BT3和CT8）对鹰嘴豆生长促进和锌生物强化的影响。原子吸收光谱法用于确定植物中的锌含量。在二十四个ZSB中，只有两个菌株（BT3和CT8）能够溶解所有三个锌源。分离后，BT3从ZnCO _3中释放出最大浓度的Zn （150.2±1.1 mg l^-1），而CT8分别从ZnO（130.2±1.2 mg l ^-1）和Zn ₃（PO ₄）₂（116.5±1.2 mg l ^-1）释放最大。培养基的pH值呈强酸性，范围为5.2至3.9，有机酸分析显示己酸，戊酸和扁桃酸是分离物产生的主要有机酸。的存在祖尔基因表示参与祖尔这些菌株介导的分子机制。这些分离株还显示出促进植物生长的性状，例如吲哚乙酸（IAA），氨，铁载体和磷酸盐增溶的产生。16S rRNA序列分析表明，两种分离株均与枯草芽孢杆菌相似。接种菌株BT3和CT8可以改善鹰嘴豆的生长参数，并使植物对锌的吸收增加3.9–6.0％。ALT。B. altitudinis菌株（BT3和CT8）显示出出色的溶解不溶性锌化合物的能力，如锌的氧化物，磷酸盐和碳酸盐，使其成为改善锌吸收和鹰嘴豆生长的重要来源。