Global isolation and classification of Azospirillum species by a new method

固氮菌是一种与植物根系共生的固氮菌，能促进植物生长。本种的分离是困难的，它们的分类和它们的寄主植物之间的关系还没有很好地阐明。本研究的目的是尽可能多地分离出这些物种，并利用质谱依赖的方法对其进行分类，并通过发现新的物种来对物种的分类提供新的见解。我们发现微氧条件下的无氮培养基对它们的分离很重要，共分离到60个菌株。对它们进行质谱分析以进行精确分类。我们还发现了一些能够促进水稻生长20%的物种。

Azospirillum species is azotrophic bacteria symbiotic to plant roots, and capable of promoting plant growth. Isolation of this species is difficult, and their classification and relationship between their host plants is not well elucidated. This study aims to isolate the species as many as possible, to classify them using mass-spectrometry dependent method, and to give a new insight into the classification of the species by finding new species. We found that nitrogen-free medium under micro-aerobic condition is important for their isolation, and we isolated 60 isolates. They were subjected to mass spectrometry for precise classification. We also found some species capable of promoting rice growth by 20%.