Unidad de Investigación, Hospital Universitario de Salamanca, Spain; Instituto de Investigación Biomédica, Salamanca, Spain.
Syst Appl Microbiol. 2013 Dec;36(8):565-71. doi: 10.1016/j.syapm.2013.09.003. Epub 2013 Oct 26.
Genus Bradyrhizobium includes slow growing bacteria able to nodulate different legumes as well as species isolated from plant tumours. The slow growth presented by the members of this genus and the phylogenetic closeness of most of its species difficults their identification. In the present work we applied for the first time Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) to the analysis of Bradyrhizobium species after the extension of MALDI Biotyper 2.0 database with the currently valid species of this genus. With this methodology it was possible to identify strains belonging to phylogenetically closely related species of genus Bradyrhizobium allowing the discrimination among species with rrs gene identities higher than 99%. The application of MALDI-TOF MS to strains isolated from nodules of different Lupinus species in diverse geographical locations allowed their correct identification when comparing with the results of rrs gene and ITS analyses. The nodulation of Lupinus gredensis, an endemic species of the west of Spain, by B. canariense supports the European origin of this species.
缓生型根瘤菌属包括能够结瘤不同豆科植物的缓慢生长的细菌以及从植物肿瘤中分离出来的物种。该属的大多数成员生长缓慢，且亲缘关系密切，这给它们的鉴定带来了困难。在本研究中，我们首次应用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）对缓生型根瘤菌属的物种进行分析，方法是用该属当前有效的物种扩展 MALDI Biotyper 2.0 数据库。利用该方法，可以鉴定出亲缘关系密切的种内菌株，从而能够区分 rrs 基因同一性高于 99%的种。将 MALDI-TOF MS 应用于从不同地理位置的不同羽扇豆属植物根瘤中分离的菌株，通过与 rrs 基因和 ITS 分析的结果进行比较，可对其进行正确的鉴定。西班牙西部特有种 Lupinus gredensis 由 B. canariense 结瘤，支持该物种起源于欧洲。
