毛竹耐铅内生细菌分离及其16S rDNA鉴定

铅污染是当前土壤重金属污染亟待解决的难题之一，利用微生物与树木的互作来修复铅污染土壤是一个行之有效的方法。为了给利用植物内生细菌提升植物修复铅污染土壤效率提供支持，以毛竹的芽和叶为材料，分离耐铅内生细菌，采用生理分析和分子鉴定相结合的方法，对分离到的菌种进行鉴定。结果发现，在不同铅离子浓度的胁迫下，从毛竹芽和叶组织中分离出27株内生细菌，革兰氏染色和VP实验均为阳性。过氧化氢酶实验中，24株表现为阳性(+)，3株为阴性(-)；甲基红实验测定结果为阳性(++)4株、弱阳性(+)20株、阴性(-)3株。对细菌提取DNA，并PCR扩增16S rDNA序列，通过BLAST比对分析，并用MEGA软件建立发育树等分子鉴定手段，初步推断分离得到的内生细菌为假单胞菌属、蜡样芽孢杆菌和不动杆菌属。

Isolation and 16S rDNA Identification of Pb-resistant Endophytic Bacteria Isolated from Phyllostachys pubescens

Lead pollution is one of the difficult problems to be solved urgently in soil heavy metal pollution at present. It is an effective method to repair lead-contaminated soil by interaction between microorganisms and trees. In this paper, the lead-tolerant endophytic bacteria from the stems and leaves of Phyllostachys pubescens were isolated and purified, and the strains were identified by physiological analysis and molecular identification. Results showed that a total of 27 endophytic bacteria were isolated under different concentrations of lead stress, which were positive by Gram staining and VP test, 24 strains were positive (+) and 3 strains were negative (-) in catalase test. The results of methylene red test showed that 4 strains were positive (++), 20 strains were weak positive (+) and 3 strains were negative(-), and the 16S rDNA sequence was amplified by PCR. By means of molecular identification methods such as BLAST, comparative analysis and establishment of phylogenetic tree with MEGA software, it was preliminarily inferred that the endophytic bacteria isolated were Pseudomonas, Bacillus cereus and Acinetobacter.