Bacterial Community in Mangrove Rhizosphere and Non-Rhizosphere and its Occurred Changes During the Acclimation Under Pyrene Stress

Abstract

Although, bacterial abundance in rhizosphere and non-rhizosphere in terrestrial plants is thoroughly investigated, the trend in the mangrove ecosystem, which the environmental conditions are regularly changed is poorly documented. Furthermore, the bacterial acclimation under stress of heavy molecular weight organic pollutants process remains obscure about the taxonomic changes that may occur. In order to address these cited issues, this study was conducted in both rhizosphere and non-rhizosphere at different depths layer of the coastal mangrove of Yunxiao. Although the physicochemical properties in both rhizosphere and non-rhizosphere were unevenly distributed, no difference was observed about both rhizosphere and non-rhizosphere bacterial abundance. Moreover, the abundance at 5-10 cm of deep was significantly higher in both rhizosphere and non-rhizosphere. This could be attributed to the high available nutrients in the surface layer. The result of bacterial acclimation under pyrene stress revealed that pyrene significantly impacted the bacterial community composition and abundance. Nonetheless, a functional community of bacteria tolerant and surviving under pyrene stress was identified and the apparition of new phylopytes were favorable to the stability of the community as well as to the remediation of the polluted environment. The general results of this study elucidated that bacterial abundance in rhizosphere and non-rhizosphere of mangrove ecosystem could be different to that in terrestrial plants, and the domestication of functional bacteria could be an excellent asset for the adaptation of bacterial communities to environmental disturbances.