Genetic diversity of cultivable bacteria of dominant plants in a potassium mine tailing of Nanjing

Abstract:

Abstract: [Objective] Plant rhizosphere bacteria play an important role in biogeochemical cycles. Microbial diversity of cultivable bacteria from soil-plant-mineral system in a mine tailing was assessed. [Methods] Cultivable bacteria were isolated by plating and screening from plant root, rhizosphere and bulk soils of predominant plants in a mine tailing of Nanjing, Jiangsu Province. Phylogenetic analyse based on 16S rDNA sequence comparisons and amplified rDNA restriction analysis of isolates were investigated. [Results] In total, 60 pure cultures were isolated; they could be grouped into 18 different operational taxonomic units (OTU) at the similarity level of 60%. Nineteen bacterial strains belonged to eleven genera (Rhizobium, Pseudomonas, Pantoea, Arthrobacter, Microbacterium, Bacillus, Paenibacillus, Acinetobacter, Sphingomonas, Kocuria, Mitsuaria) of three major phylogenetic groups (Proteobacteria, Actinobacteria, Firmicutes). Rhizobium, Pseudomonas and Pantoea were the dominant groups. [Conclusion] Different cultivable bacteria inhabited in roots and soils of dominant plants in the mine tailing. They might play a certain role in the soil-plant-mineral environment.