【摘要】 从上海郊区菠菜(Spinacia oleracea)根瘤中分离到一株革兰氏阴性杆菌,编号为84G,回接试验表明能感染菠菜幼苗并结瘤。细胞大小为0.5～0.8×1.3～2.3μm,能运动,以1至数根端生鞭毛为主;并有纤毛,好氧,具有呼吸代谢类型。氧化酶和接触酶阳性,硝酸盐还原,有聚β-羟基丁酸盐颗粒形成。产生精氨酸双水解酶,石蕊牛奶产碱并还原,明胶液化,不水解淀粉,不产生3-酮基乳糖,能在含甘露醇和其他糖类的培养基中产酸,能在含0.5～6%的 NaCl 培养基上生长,最适生长温度为28～30℃,最适 pH 为6～7,DNA 中 G+C 含量为64.5mol%。因此,菌株84G 可归根瘤菌属,但与属中已有的种有明显的差别,现将其定为新种,命名为菠菜根瘤菌Rhizobium spinacia sp.nov.。更多还原

【Abstract】 A strain of Gram negative bacterium No.84G was isolated from root nodules of Spinacia oleracea in the suburbs of Shanghai.The[strain 84G infected spinach by reinoculation and formed nodule on the roots.Cell diameter is 0.5-0.8μm,cell length,1.3-2.3μm.Motile by means of polar flagella which are either single or in small tufts.It has fimbriae.Aero- bic,possessing a respiratory type of metabolism with oxygen as the ter- minal electron acceptor.Main characteristics of the strain 84G are oxidase and catalase positive,nitrate reduced,PHB accumulation,arginine dihy- drolase positive,litmus milk alkaline and reduced,gelatin hydrolyzed, starch not hydrolzed,3-ketoglycosides not produced and acidic reaction in medium containing mannitol and other carbohydrates.Growth occurs in agar medium containing 0.5-6% NaCl.Optimum temperature,28-30℃, Optimum pH,6-7.The strain was present in root nodules as pleomor- phic forms which could fix nitrogen.G+C content in DNA is 64.5 mol% (Tm).Accordingly,bacterium No.84G should be attributed to Rhizobium. Although it is similar to known speices of Rhizobium,there are some diffe- rences obviously as above mentioned.We propose a new species name- Rhizobium spinacia sp.nov.更多还原