Alves Artur, Riesco Raúl, Correia António, Trujillo Martha E
Departamento de Biologia, CESAM, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
Departamento de Microbiología y Genética, Edificio Departamental, Lab 214, Campus Miguel de Unamuno, Universidad de Salamanca, 37007 Salamanca, Spain.
Int J Syst Evol Microbiol. 2015 Jun;65(Pt 6):1794-1798. doi: 10.1099/ijs.0.000177. Epub 2015 Mar 5.
An endophytic actinobacterial strain RZ36T, isolated from roots of the salt-marsh plant Halimione portulacoides, was subjected to a polyphasic taxonomic characterization. 16S rRNA gene sequence analysis revealed that this strain belonged to the genus Microbacterium. The closest phylogenetic relative was Microbacterium hominis DSM 12509T, with a pairwise 16S rRNA gene sequence similarity of 98.8 %. The DNA-DNA hybridization value between strain RZ36T and M. hominis DSM 12509T was 16 %. The affiliation to the genus Microbacterium was corroborated by phenotypic and chemotaxonomic characteristics. The cell-wall peptidoglycan type was B2β and the diagnostic diamino acid was ornithine. Whole-cell sugars detected were galactose, glucose, rhamnose, ribose and xylose. The major fatty acids were anteiso-C15 : 0 and iso-C16 : 0 and the major menaquinone was MK-11 (64 %). Main polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. The genomic DNA G+C content was 69.7 mol%. Thus, on the basis of phenotypic, genotypic and chemotaxonomic data, strain RZ36T is considered to represent a novel species of the genus Microbacterium, for which the name Microbacterium proteolyticum sp. nov. (type strain RZ36T = DSM 27100T = CECT 8356T) is proposed.
从盐沼植物滨藜（Halimione portulacoides）根部分离得到的一株内生放线菌RZ36T，进行了多相分类学特征分析。16S rRNA基因序列分析表明，该菌株属于微杆菌属（Microbacterium）。最接近的系统发育亲缘种是人类微杆菌（Microbacterium hominis）DSM 12509T，16S rRNA基因序列的两两相似性为98.8%。菌株RZ36T与人类微杆菌DSM 12509T之间的DNA-DNA杂交值为16%。表型和化学分类学特征证实了其属于微杆菌属。细胞壁肽聚糖类型为B2β，诊断性二氨基酸为鸟氨酸。检测到的全细胞糖类有半乳糖、葡萄糖、鼠李糖、核糖和木糖。主要脂肪酸为anteiso-C15 : 0和iso-C16 : 0，主要甲基萘醌为MK-11（64%）。主要极性脂由双磷脂酰甘油、磷脂酰甘油和两种未知糖脂组成。基因组DNA G+C含量为69.7 mol%。因此，基于表型、基因型和化学分类学数据，菌株RZ36T被认为代表微杆菌属的一个新物种，为此提出名为解蛋白微杆菌（Microbacterium proteolyticum）新种（模式菌株RZ36T = DSM 27100T = CECT 8356T）。
