摘要
从大白菜软腐组织中分离出一株软腐病细菌BC1,经过形态观察、生理生化特性分析、致病性检测和 16SrDNA序列分析 ,该分离物被鉴定为胡萝卜软腐欧文氏菌胡萝卜亚种 (Erwiniacarotovorasubsp .carotovora ,Ecc)的一个新菌株 ,编号为BC1。这是首次从 16SrDNA序列水平上对在我国分布的软腐欧文氏菌进行鉴定。EccBC1的 16SrDNA序列与其它软腐欧文氏菌株的 16SrDNA序列之间同源性达 98 7%～ 99 3% ,而且在系统发育树中独立于Ecc其它菌株。序列分析结果表明 ,EccBC1具有至少 2种不同的 16SrDNA序列 ,它们都在第 4 5 9位和 4 73位 (相对于大肠杆菌 16SrDNA序列 )发生碱基突变 ,同一基因中两个突变位点之间彼此互补 ,处于 16SrRNA螺旋H17颈部 ,而且这两处碱基变异只存在于BC1菌株中。通过与其它软腐欧文氏菌亚种和菌株 16SrDNA序列进行比对分析 ,还进一步鉴定出一些BC1菌株特异的 16SrDNA碱基突变位点。本文报道的EccBC1两个 16SrDNA序列在GenBank中的登录号分别为AY30 90 6 8和AY30 90 6 9。
A new strain, BC1, of Erwinia carotovora subsp. carotovora was isolated from soft-rotted Chinese cabbage. The strain was characterized by morphological observation, biochemical and physiological identification, pathogenicity determination and 16S rDNA sequence analysis. 16S rDNA sequence of the BC1 showed 98.7%～99.3% sequence identity with those of other Erwinia carotovora subspecies and strains. At least two different 16S rDNA sequences are present in the BC1 genome, each having two mutation sites located at positions 459 and 473, respectively. The two mutations occur at the stem of helix H17 in the 16S rRNA secondary structure and are complementary to each other in each of the two sequences. DNA sequence alignment showed that the two mutations are Ecc BC1-specific, and further analysis has detected more BC1-specific mutations among the 16S rDNA sequences of Ecc. Phylogenetic analysis of the 16S rDNA sequences indicated that the BC1 is distinct from other strains within the Ecc group. The Ecc BC1 16S rDNA sequences reported here have the accession numbers AY309068 and AY309069 in GenBank.
出处
《微生物学报》
CAS
CSCD
北大核心
2004年第2期136-140,共5页
Acta Microbiologica Sinica
基金
国家"8 63计划"( 2 0 0 1AA2 3 10 8)~~
