一株分离自含羞草的β-根瘤菌的生物学特性研究

从海南尖峰岭自然保护区巴西含羞草的根瘤中分离到一株根瘤菌,编号为caf324,经过16S rDNA全序列测定和系统发育分析,发现caf324与β-根瘤菌含羞草伯克霍尔德菌PAS44(AY752958)的亲缘关系很近,相似度达到99.7%。通过部分生理生化测定发现,caf324接触酶、氧化酶和硝酸盐还原试验均为阳性,不能利用明胶和淀粉,不能利用葡萄糖发酵产酸,不能水解酪素,不能产生吲哚和3-酮基乳糖;抗逆性研究表明,caf324的生长范围广,可耐2%的NaCl,耐酸碱(pH4～11),最高生长温度45℃。

Biological characteristics of Burkholderia sp.caf324 isolated from Mimosa invisa

Isolated from root nodules of Mimosa invisa Mart. ex Colla in the Jianfengling National Nature Reserve, Hainan Province, a representative strain, caf324, was analyzed by 16S rDNA sequencing, physical and chemical properties test. The 16S rDNA sequence was compared with related rhizobia and an unrooted phylogenetic tree was produced. The results show that caf324 is clustered together with β-rhizobia of Burkholderia mimosarum PAS44 (AY752958), with a similarity of 99.7%. Biological characteristics of this caf324 strain were tested, showing the following results: catalase and oxidase were positive, indole was not found, gelatin was not hydrolysed and glucose was unable to generate acid through fermentation. It can endure 2% NaCl and grow in media with pH of 4--11, under the temperatures up to 45℃.