Iron- and methane-cycling are important processes in wetlands with one connected to plant growth and the other to greenhouse gas emission, respectively. In contrast to acidic habitats, there is scarce information on the ecology of microbes oxidizing ferrous iron at circum-neutral pH. The latter is mainly due to the lack of isolated representatives and molecular detection techniques. Recently, we developed PCR-DGGE and QPCR assays to detect and enumerate Gallionella-related neutrophilic iron-oxidisers (FeOB) enabling the assessment of controlling physical as well as biological factors in various ecosystems. In this study, we investigated the spatial distribution of Gallionella-related FeOB in co-occurrence with methane-oxidizing bacteria (MOB) in a riparian wetland. Soil samples were collected at different spatial scales (ranging from meters to centimeters) representing a hydrological gradient. The diversity of FeOB was assessed using PCR-DGGE and the abundance of both FeOB and MOB by QPCR. Geostatistical methods were applied to visualize the spatial distribution of both groups. Spatial distribution as well as abundance of FeOB and MOB was clearly correlated to the hydrological gradient as expressed in moisture content of the soil. Gallionella-related numbers of FeOB outnumbered the MOB subgroups indicating their competitiveness or the prevalence of Fe2+ over CH4 oxidation in this floodplain.
|Tijdschrift||Frontiers in Microbiology|
|Status||Gepubliceerd - 2012|