Abstract: One fast-growing Rhizobium strain K_164n was isolated from root nodules of Leucaena diversifolia. It was Gran-negative rod (2.2×0.89 μm) with subpolar flagella. Long doubling time (1.69 hr) in YM liquid medium was observed. It grew well at 30℃ and did not grow both at 39℃ and in 0.5% NaCl. The growth had a pH ranging from 4.5 to 6.6. Physiological and biochemical characteristics of strain K_164m were systematically studied. When inoculated, nodules was formed on the host plants. The nitrogenase activity was determined. Expression of H₂ uptake activity of strain K_164n in free-living was investigated.

Key words: Leucaena diverstheia, Rhizobium, Characteristics

摘要： 从异叶银合欢K₁₆₄和K₇₉₄的根瘤中各分离到一株根瘤菌,并且,对K₁₆₄根瘤菌的形态特征和生理生化特性进行了研究。K₁₆₄根瘤菌在平板上培养2天,菌落呈圆形,灰白色,直径约1.2 mm;革兰氏染色呈阴性,无芽孢,有美膜,两根极生鞭毛;杆菌大小为2.2×0.89 μm,增代时间为1.69小时,属快生型;最适生长温度为30℃,在39℃持续2天不能存活,在20℃以下不能生长;不耐盐,较耐酸,在pH 4.5~6.6范围内均能生长,但不耐碱;对庆大霉素和青霉素敏感;对供试的10种糖都能利用,不液化明胶,不利用淀粉,B.T.B试验未变色,不能进行3-酮基乳糖反应,硝酸盐反应呈阳性,石蕊牛奶试验能胨化、还原、产碱,牛肉膏蛋白胨培养生长差,能利用柠檬酸盐;在自生条件下具有吸H2酶活性;回接后结瘤率达100%,根瘤具有固氮酶和吸H₂酶活性。

关键词: 异叶银合欢, 根瘤菌, 特性