Abstract
Purpose: Spatial distribution on a regional scale of the rhizobacterial communities of Phragmites australis stands was investigated along the Yellow River watershed, China. Materials and methods: Samples were collected along a secondary and the main drainage canals. Amplified ribosomal intergenic spacer analysis (ARISA) and pyrosequencing were performed to study the diversity of microbial communities. Bacterial functionality was characterized using a functional inference-based (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States, PICRUSt) approach. Results and discussion: Microbial community structure resulted to be primarily driven by phosphorus, nitrogen, mercury, chromium, and nickel. At genus level, taxa related to bioremediation, in particular Thiobacillus and Flavobacterium, and plant growth-promoting bacteria, such as Lysobacter, were found to be stably associated with P. australis. Genera related to fecal contamination such as Faecalibacterium, were recorded in three sampling sites. Rhizobacterial communities showed a significant fraction of taxa related to the xenobiotic metabolism and degradation. Conclusions: Rhizobacterial communities were influenced by the multiple effects of the different environmental parameters. Moreover, the rhizosphere of P. australis can be considered potentially a source of bacterial taxa useful for bioremediation and growth-promoting activities of plants.