耐镉产铁载体菌株的分离及鉴定

Isolation and identification of a cadmium-resistant and siderophores-producing strain

从黑麦草(Lolium perenne L.)根际土壤中分离到1株耐镉产铁载体细菌LY02,经形态观察和16S r DNA序列测定以及同源性分析鉴定为巨大芽孢杆菌(Bacillus megaterium)。该菌株能够分泌吲哚乙酸(IAA),促进磷的溶解,有利于提高黑麦草种子发芽率和抵抗镉胁迫的能力,因此可以与黑麦草互利共生。该菌株对Cd2+的最大耐受质量浓度为10 mg/L,可以促进土壤中的镉向可溶性的生物有效态转化,从而有利于黑麦草对镉的富集。

A cadmium-resistant and siderophore-producing strain was isolated from rhizospheric soil of Lolium perenne L.. Through morphological observation and 16 S r DNA sequencing determination( including homology analysis),the strain was identified as Bacillus megaterium. This strain could produce indole-3-acetic acid and accelerate phosphorus dissolved. Moreover,the strain could promote the germination rate of Lolium perenne L. seeds and resist Cd stress. Therefore,Bacillus megaterium and Lolium perenne L. could benefit each other. The maximum tolerant Cd2+mass concentration of Bacillus megaterium was 10 mg/L. At the same time,the Bacillus megaterium could transform Cd into dissolved bio-available form,easy for Lolium perenne L. to accumulate.