Thailand Bioresource Research Center, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
Division of Microbiology, Department of Science, Faculty of Liberal Arts and Science, Kasetsart University Kamphaeng Saen Campus, Nakorn Pathom, 73140, Thailand.
J Microbiol Biotechnol. 2022 Nov 28;32(11):1435-1446. doi: 10.4014/jmb.2206.06058. Epub 2022 Oct 17.
Zinc-solubilizing bacteria can convert the insoluble form of zinc into soluble forms available to plants. This study was conducted to isolate and screen zinc-solubilizing actinobacteria from rhizosphere soils and to assess their effect on vegetable soybean growth. In total, 200 actinobacteria strains belonging to 10 genera were isolated from rhizosphere soil samples. Among these isolates, four showed zinc solubilization with solubilizing index values ranging from 3.11 to 3.78 on Bunt and Rovira agar supplemented with 0.1% zinc oxide. For the quantitative assay, in broth culture, strains CME34 and EX51 solubilized maximum available zinc contents of 529.71 and 243.58 μg/ml. Furthermore, indole-3-acetic acid (IAA) and ammonia were produced by these two strains, the strain CME34 produced the highest amount of IAA 4.62 μg/ml and the strain EX51 produced the highest amount of ammonia 361.04 μg/ml. In addition, the phosphate-solubilizing abilities in Pikovskaya's medium of CME34 and EX51 were 64.67 and 115.67 μg/ml. Based on morphological and biochemical characterization and 16S rDNA sequencing, the strains CME34 and EX51 were closely related to the genus . In a greenhouse experiment, single-strain inoculation of sp. CME34 or EX51 significantly increased the shoot length, root length, plant dry weight, number of pods per plant and number of seeds per plant of vegetable soybean plants compared to the uninoculated control. These findings facilitated the conclusion that the two strains have potential as zinc solubilizers and can be suggested as bioinoculants to promote the growth and yield of soybean.
锌溶细菌可以将锌的不溶性形式转化为植物可用的可溶性形式。本研究从根际土壤中分离和筛选锌溶放线菌,并评估它们对蔬菜大豆生长的影响。从根际土壤样本中分离出 200 株属于 10 个属的放线菌。在这些分离物中,有 4 株在添加 0.1%氧化锌的 Bunt 和 Rovira 琼脂上显示出锌溶解作用,溶解释放指数值在 3.11 到 3.78 之间。对于定量测定,在肉汤培养中,菌株 CME34 和 EX51 溶解释放最大的有效锌含量分别为 529.71 和 243.58 μg/ml。此外,这两株菌都能产生吲哚-3-乙酸(IAA)和氨,菌株 CME34 产生的 IAA 最高,为 4.62 μg/ml,菌株 EX51 产生的氨最高,为 361.04 μg/ml。此外,CME34 和 EX51 在 Pikovskaya 培养基中的解磷能力分别为 64.67 和 115.67 μg/ml。根据形态学和生物化学特征以及 16S rDNA 测序,菌株 CME34 和 EX51 与属 密切相关。在温室试验中,与未接种对照相比,单菌株接种 sp. CME34 或 EX51 显著增加了蔬菜大豆植株的茎长、根长、植株干重、每株豆荚数和每株种子数。这些发现表明,这两种 菌株具有作为锌溶菌的潜力,可以作为生物接种剂来促进大豆的生长和产量。