Earlier studies have focused on cell counts and the activity of bacteria in the reed rhizosphere using cultivation-based techniques (Borsodi et al., 2003). Others have focused

on the community structure and diversity of buy Fulvestrant bacteria associated with the reed rhizosphere in freshwaters using molecular methods (Borsodi et al., 2007; Ravit et al., 2007; Rusznyak et al., 2007; Vladar et al., 2008), but no study has examined the endophytic bacteria associated with reed roots and their possible roles in phytoremediation mediated by reed wetland. This paper describes the diversity and community structure of endophytic bacteria in reed roots growing in a constructed wetland. We used the 16S rRNA library technique, a culture-independent method, with the goal of understanding the role of bacteria within reed roots in enhancing the phytoremediation of eutrophic water mediated by reed-constructed wetland. Reed roots were obtained see more from the common reed (P. australis Cav. Trin.) zone of Beijing CuiHu Wetland, China, in July 2008. The wetland was used to treat a mixture of domestic wastewater from the surrounding area and water from Shangzhuang reservoir. In this study, one treatment region with marshy

plants (mainly reed) and one control region (without any plants) were chosen to measure the water quality, in order to determine the effect of reed on the water body. The control region shared the same water source with the reed planted region, but was 50 m away from it. The physicochemical characteristics

of the water in the treatment region were as follows: pH 7.34, 1.37 mg L−1 total nitrogen (N), 0.13 mg L−1 total phosphorus (P), and 27.85 mg L−1 organic matter. In the control region, the water quality indexes were as follows: pH 7.56, 3.11 mg L−1 total nitrogen, 0.25 mg L−1 total phosphorus, and 31.90 mg L−1 organic matter. The observations and sampling GPX6 took place in July 2008. The reed roots were sampled from 15 cm below the water surface within the treatment region. Three samples of 1 g fibrous roots were taken from three different locations with a distance of about 10 m. They were immediately mixed and transported to the laboratory. Reed roots were first washed three times with tap water to remove attached soil. Subsequently, the roots were immersed in 70% ethanol for 3 min, washed with a fresh sodium hypochlorite solution for 5 min, rinsed three times with 70% ethanol for 30 s, and finally washed five times with sterile-distilled water as described in Sun et al. (2008). To confirm that the disinfection process was successful, aliquots of the sterile-distilled water used in the final rinse were set on Luria–Bertani (LB) medium plates. The plates were examined for bacterial growth after incubation at 30 °C for 3 days.