关键词: 重金属, 小飞蓬, 内生细菌, 菌株特性, 16S rDNA

Abstract: In order to broaden the bioremediation of heavy metal contaminated soil and enrich the resource library of functional strains,six strains of manganese-resistant endophytic bacteria were isolated from the leaves of Conyza canadensis,named XFP-01—06,with the tolerance to 800—2 500 mg/L Mn²⁺.Among them,four strains also showed high tolerance to Pb²⁺ and Cr⁶⁺,of which XFP-04 strain was the most outstanding,and the highest tolerable contents of Mn²⁺,Pb²⁺,Cr⁶⁺were 2 500,800,and 400 mg/L,respectively.It also had the promotion characteristics of IAA production,iron carrier production,nitrogen fixation,and phosphorus dissolution,and also could withstand high osmotic pressure,so it was a potential dominant strain for bioremediation of heavy metal contaminated soil.Through the determination of physiological and biochemical characteristics and 16S rDNA sequence analysis,the strain XFP-04 was identified as Bacillus cereus.

Key words: Heavy metal; Conyza canadensis, Endophytic bacteria, Strain characteristics, 16S rDNA