Struktur-/Funktionsanalyse mikrobieller Gemeinschaften in gefluteten Reis-Mikrokosmen. Charakterisierung der Struktur und Dynamik mikrobieller Populationen in terrestrischen Standorten Abschlussbericht

Abstract

Direct recovery of 16S rRNA gene sequences and cultivation studies were used to characterize soil microbial communities. The cultivation studies aimed at the isolation of representatives of numerically abundant populations. Flooded rice microcosms were used as experimental model system. In principle, this system can be divided into three major compartments, namely the root system, the rhizosphere soil, and the anoxic bulk soil. The three compartments are characterized by spatial and temporal variations with respect to the availability of substrates and oxygen. Close correlations between the two methodologically independent approaches revealed members of the alpha- and beta-subclasses of Proteobacteria as characteristic inhabitants of rice roots. In contrast, members of the genera Clostridium and Bacillus, as well as of the division Verrucomicrobia and the Cytophaga/Flavobacterium/Bacteroides group were identified by the dual approach as the predominant groups in the anoxic bulk soil. In addition, it was shown that the presence or absence of oxygen represents an important environmental factor which determines the structure and diversity of bacterial communities in flooded rice paddy soil. (orig.)SIGLEAvailable from TIB Hannover: DtF QN1(85,3) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman