中文摘要：

利用微生物分离培养方法从互花米草根部和叶片获得内生细菌,经重金属筛选,分离到一种耐受重金属Cu2＋、Pb2＋和Cr6＋的细菌．为了进一步鉴定分离菌株,利用 PCR 方法扩增其部分16S rDNA 序列,目标DNA条带约1500 bp,测序和在线分析结果后显示,所测序列均与基因库中已上传的 Lysinibacillus sphaericus菌株16S rDNA 序列（KJ878614．1,JN613478．1）相似性均为100％．初步鉴定该菌为 Lysinibacillus属球形芽孢杆菌（Lysinibacillus sphaericus）,命名为Lysinibacillus sphaericus QZ1-1．对该菌株采用促生长特性分析结果显示,该菌株具有产生 IAA和 ACC的能力,同时该菌能在无氮培养基中生长,具备固氮功能,为日后重金属污染生物修复相关研究提供了良好的目标菌株．

英文摘要：

Endophytic bacteria were obtained from roots and leaves of Spartina alterniflora using cul-ture-dependent method.After heavy metal screening,a strain showed resistance to Cu2＋,Pb2＋ and Cr6＋ was obtained.To further characterize the isolation,partial 16S rDNA with length 1 500 bp was amplificated and sequenced.Online analysis suggested that all sequences showed 100% sequence identi-ty to previously submitted strains Lysinibacillus sp.ES3-1 （KJ 878614.1）and Lysinibacillus sp.O-E16 （JN 613478.1）.We infered the isolation belongs to Lysinibacillus sphaericus,named Lysinibacil-lus sphaericus QZ1-1 .Growth characteristic analysis indicated that this strain could produce IAA and ACC deaminase,grow in nitrogen-free medium,suggesting its ability of nitrogen fixation.This study indicated that Lysinibacillus sphaericus QZ1-1 is a strong candidate for further related studies because of its potential phytoremodiation of heavy metal pollution.