Peix Alvaro, Rivas Raúl, Mateos Pedro F, Martínez-Molina Eustoquio, Rodríguez-Barrueco Claudino, Velázquez Encarna
Instituto de Recursos Naturales y Agrobiología, CSIC, Salamanca, Spain.
Int J Syst Evol Microbiol. 2003 Nov;53(Pt 6):2067-72. doi: 10.1099/ijs.0.02703-0.
A bacterial strain (designated IH5(T)), isolated from rhizospheric soil of grasses growing spontaneously in Spanish soil, actively solubilized phosphates in vitro when bicalcium phosphate was used as a phosphorus source. This strain was Gram-negative, strictly aerobic, rod-shaped and motile. The strain produced catalase, but not oxidase. Cellulose, casein, starch, gelatin, aesculin and urea were not hydrolysed. Growth was observed with many carbohydrates as the carbon source. The main non-polar fatty acids detected were hexadecenoic acid (C(16 : 1)), hexadecanoic acid (C(16 : 0)) and octadecenoic acid (C(18 : 1)). The hydroxy fatty acids detected were 3-hydroxydecanoic acid (C(10 : 0) 3-OH), 3-hydroxydodecanoic acid (C(12 : 0) 3-OH) and 2-hydroxydodecanoic acid (C(12 : 0) 2-OH). Phylogenetic analysis of 16S rRNA indicated that this bacterium belongs to the genus Pseudomonas in the gamma-subclass of the Proteobacteria and that the closest related species is Pseudomonas graminis. The DNA G+C content was 61 mol%. DNA-DNA hybridization showed 23 % relatedness between strain IH5(T) and P. graminis DSM 11363(T). Therefore, strain IH5(T) belongs to a novel species from the genus Pseudomonas, for which the name Pseudomonas rhizosphaerae sp. nov. is proposed (type strain, IH5(T)=LMG 21640(T)=CECT 5726(T)).
从西班牙土壤中自然生长的禾本科植物根际土壤中分离出的一株细菌（命名为IH5(T)），当以磷酸二钙作为磷源时，该菌株在体外能积极溶解磷酸盐。该菌株为革兰氏阴性菌，严格需氧，杆状且具运动性。该菌株产生过氧化氢酶，但不产生氧化酶。纤维素、酪蛋白、淀粉、明胶、七叶苷和尿素均未被水解。以多种碳水化合物作为碳源时可观察到生长。检测到的主要非极性脂肪酸为十六碳烯酸（C(16 : 1)）、十六烷酸（C(16 : 0)）和十八碳烯酸（C(18 : 1)）。检测到的羟基脂肪酸为3-羟基癸酸（C(10 : 0) 3-OH）、3-羟基十二烷酸（C(12 : 0) 3-OH）和2-羟基十二烷酸（C(12 : 0) 2-OH）。16S rRNA的系统发育分析表明，该细菌属于变形菌门γ亚类中的假单胞菌属，与之亲缘关系最近的物种是禾本科假单胞菌。DNA G+C含量为61 mol%。DNA-DNA杂交显示菌株IH5(T)与禾本科假单胞菌DSM 11363(T)之间的相关性为23%。因此，菌株IH5(T)属于假单胞菌属的一个新物种，为此提出名为根际假单胞菌（Pseudomonas rhizosphaerae sp. nov.）（模式菌株，IH5(T)=LMG 21640(T)=CECT 5726(T)）。
