Phosphate-solubilizing bacteria can release phosphorus (P) from insoluble minerals and benefit either soil fitness or plant growth. Bulk sized P compounds have been suggested but little is known about solubilization of nanosized materials such as hydroxyapatite nanoparticles (HANP). A screening of the initial 43 strains from vanilla rhizospheres for phosphate solubilization with bulk Ca3(PO4)2 was carried out. Subsequently, 6 strains were selected on bulk rock phosphate (RP) and HANP. Two kinetics experiments were run out regarding evaluation at 5, 10 and 20 days after inoculation (dai). Bacterial biomass production was similar in both experiments; the lowest biomass was found at 20 dai. In all cases, bacteria reduced the original culture medium pH; which was related with phosphate solubilization from the production of organic acids. Citric acid was produced by all strains. Enterobacter cloacae CP 31 was the most interesting bacterium: produced the lowest culture pH at 20 dai (4) with both Ca3(PO4)2 and RP, and 3.7 at 10 dai with HANP correlating with high soluble P concentration (536, 64 and 13 mg L-1 with these P sources, respectively). This bacterium should be tested as an inoculant in plants to reveal its potential as plant promoter growth and HANP to suggest its role in the potential use of nano-P fertilizers.

中文翻译：

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用本体磷酸三钙和羟基磷灰石纳米粒子筛选细菌的磷酸盐增溶。

解磷细菌可以从不溶性矿物质中释放磷（P），有利于土壤适应性或植物生长。已经提出了大尺寸的P化合物，但是对于诸如羟基磷灰石纳米颗粒（HANP）的纳米材料的增溶了解很少。从香草根际中筛选了最初的43个菌株，用大量Ca3（PO4）2溶解了磷酸盐。随后，在大块磷酸盐（RP）和HANP上选择了6个菌株。关于接种后第5、10和20天（dai）的评估进行了两个动力学实验。在两个实验中细菌生物量的产生是相似的。生物量最低的是20天。在所有情况下，细菌都会降低原始培养基的pH；这与有机酸生产中的磷酸盐增溶有关。柠檬酸由所有菌株产生。阴沟肠杆菌CP 31是最有趣的细菌：在20 dai（4）时产生的培养pH值最低，同时具有Ca3（PO4）2和RP，在10 dai时产生3.7的HANP与高可溶性P浓度相关（536、64和13）毫克L-1与这些P来源）。该细菌应作为植物的孕育剂进行测试，以揭示其作为植物启动子生长的潜力，而HANP则表明其在纳米P肥料的潜在用途中的作用。