Peng Guixiang, Yuan Qinghua, Li Huaxing, Zhang Wu, Tan Zhiyuan
College of Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China.
Int J Syst Evol Microbiol. 2008 Sep;58(Pt 9):2158-63. doi: 10.1099/ijs.0.65632-0.
During a study of endophytic nitrogen-fixing bacteria present in the wild rice species Oryza alta, eight novel isolates were obtained from surface-sterilized roots and classified in the genus Rhizobium on the basis of almost-complete 16S rRNA gene sequence analysis. These strains can nodulate Phaseolus vulgaris and Glycine max. The highly similar protein patterns, DNA fingerprint patterns of insertion sequence-based PCR (IS-PCR) and DNA-DNA hybridizations showed that these novel isolates were members of the same species. The closest phylogenetic relatives of the representative strain Alt 505(T) of the novel group were Rhizobium etli CFN 42(T) and Rhizobium indigoferae CCBAU 71714(T), with 96.2 and 96.0% 16S rRNA gene sequence similarity, respectively. Low DNA-DNA relatedness with the type strains of R. etli, R. indigoferae, Rhizobium hainanense, Rhizobium mongolense and Rhizobium galegae and differences in IS-PCR fingerprinting patterns, SDS-PAGE of proteins, antibiotic resistance, phenotypic tests and comparison of cellular fatty acids with Rhizobium species indicated that the novel group of isolates were distinct from previously described species. Based on these results, we propose to place them in a novel species, as Rhizobium oryzae sp. nov. The type strain is Alt 505(T) (=LMG 24253(T) =CGMCC 1.7048(T)).
在一项对野生稻种高秆野生稻内生固氮细菌的研究中，从表面消毒的根部获得了8株新分离株，并基于几乎完整的16S rRNA基因序列分析将其归类于根瘤菌属。这些菌株能够使菜豆和大豆结瘤。高度相似的蛋白质图谱、基于插入序列的PCR（IS-PCR）的DNA指纹图谱以及DNA-DNA杂交表明，这些新分离株属于同一物种。该新类群的代表菌株Alt 505(T)最接近的系统发育亲缘种是费氏中华根瘤菌CFN 42(T)和栖靛根瘤菌CCBAU 71714(T)，16S rRNA基因序列相似性分别为96.2%和96.0%。与费氏中华根瘤菌、栖靛根瘤菌、海南根瘤菌、蒙古根瘤菌和山羊豆根瘤菌的模式菌株的低DNA-DNA相关性，以及IS-PCR指纹图谱、蛋白质SDS-PAGE、抗生素抗性、表型测试的差异，以及与根瘤菌属细胞脂肪酸的比较表明，该新分离株类群与先前描述的物种不同。基于这些结果，我们建议将它们归入一个新物种，命名为稻根瘤菌（Rhizobium oryzae sp. nov.）。模式菌株是Alt 505(T)（=LMG 24253(T)=CGMCC 1.7048(T)）。
