Metabolic potential and community structure of endophytic and rhizosphere bacteria associated with the roots of the halophyte Aster tripolium L.

Publication date: January 2016 Source:Microbiological Research, Volume 182 Author(s): Sonia Szymańska, Tomasz Płociniczak, Zofia Piotrowska-Seget, Michał Złoch, Silke Ruppel, Katarzyna Hrynkiewicz The submitted work assumes that the abundance and diversity of endophytic and rhizosphere microorganisms co-existing with the halophytic plant Aster tripolium L. growing in a salty meadow in the vicinity of a soda factory (central Poland) represent unique populations of cultivable bacterial strains. Endophytic and rhizosphere bacteria were (i) isolated and identified based on 16S rDNA sequences; (ii) screened for nifH and acdS genes; and (iii) analyzed based on selected metabolic properties. Moreover, total microbial biomass and community structures of the roots (endophytes), rhizosphere and soil were evaluated using a cultivation-independent technique (PLFA) to characterize plant–microbial interactions under natural salt conditions. The identification of the isolated strains showed domination by Gram-positive bacteria (mostly Bacillus spp.) both in the rhizosphere (90.9%) and roots (72.7%) of A. tripolium. Rhizosphere bacterial strains exhibited broader metabolic capacities, while endophytes exhibited higher specificities for metabolic activity. The PLFA analysis showed that the total bacterial biomass decreased in the following order (rhizosphere<soil<endophytes) and confirmed the dominance of Gram-positive endophytic bacteria in the roots of th...
Source: Microbiological Research - Category: Infectious Diseases Source Type: research