Rhizosphere bacterial community of Typha angustifolia L. and water quality in a river wetland supplied with reclaimed water.

Abstract

Wetland plant rhizosphere microorganisms play a significant role in the purification of ecological restoration of reclaimed water replenishment wetlands. In this study, water quality discriminant analysis indicated the wetland had a distinctive role in the purification of total nitrogen (TN), total phosphorus (TP), and nitrate (NO3 (-)) from reclaimed water, of which removal rates were 42.15, 47.34, and 28.56 % respectively. All the sequences of 16S ribosomal RNA (16S rRNA) gene clone library were affiliated with Proteobacteria (74.50 %), Bacteroidetes (6.54 %), Gemmatimonadetes (5.88 %), Chloroflexi (4.25 %), Chlorobi (2.94 %), Nitrospira (2.61 %), Acidobacteria (2.29 %), and Actinobacteria (0.98 %). Assessment of water quality purification and rhizosphere bacterial properties revealed that the major biogeochemical reactions were nitrogen, phosphorus, carbon, and sulfur cycles (33.70, 15.40, 14.40, and 4.90 %, respectively). In addition, approximately 5.90 and 4.60 % of the clones are closely related with the minor biogeochemical degradations of antibiotics and halogenated hydrocarbons, which were the typical characteristics of reclaimed water wetland different from freshwater wetlands. The finding of water quality discriminant is consistent with that of bacterial community, but the latter was a more powerful method than the former which reveals possible implications of wetland plant purification on the reclaimed water.