Research
Title: | EFFECTS OF ROOT RADIAL OXYGEN LOSS ON MICROBIAL IRON CYCLING AND PHOSPHORUS REMOVAL CHARACTERISTICS IN SUBMERGED PLANT (HYDRILLA VERTICILLATA) RHIZOSPHERE |
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First author: | Tian, Cuicui; Wang, Chunbo; Tian, Yingying; Wu, Xingqiang; Xiao, Bangding |
Journal: | FRESENIUS ENVIRONMENTAL BULLETIN |
Years: | 2017 |
DOI: | |
Abstract: | It is now well known that root radial oxygen loss (ROL) can affect the microbial activities and nutrient variations in the rhizosphere oxidized zone. Iron (Fe) plaque occurs on the roots of submersed plants where it can influence the mobility of trace metals and phosphorus (P). This study investigated the effects of root ROL on microbial Fe cycling and P removal characteristics in submerged plant rhizosphere. The results showed that root ROL can promote the formation of the rhizosphere oxidized zone. Root ROL can also change the number of total Bacteria. Specifically, Gallionella-related iron-oxidizing bacteria and Geobacter-related iron-reducing bacteria were all increased in root oxidized zone. Fe plaques contain more poorly crystalline Fe, which may affect the number of Geobacter in the rhizosphere. Owing to the dual control of Fe plaque accumulation by Fe oxidation and reduction, there are not enough binding sites for more P absorption. These results suggest that root ROL plays a very important role on Fe plaque formation, microbial Fe cycling and P adsorption in rhizosphere. |