title: Early colonizers of unoccupied habitats represent a minority of the soil bacterial community.
abstract: In order to understand (re-)colonization of microhabitats and bacterial succession in soil, it is important to understand which members of soil bacterial communities are most motile in the porous soil matrix. To address this issue, we carried out a series of experiments in sterilized soil microcosms. Using two different model strains, Pseudomonas fluorescens strain Pf0-1 and Collimonas fungivorans strain Ter331, we first determined the influence of nutrient availability on bacterial expansion rates. Based on these results, we then conducted similar microcosm experiments to examine microbial mobility within natural soil bacterial communities under a single nutrient regime. The expansion of bacterial populations within the community was assayed by quantitative PCR and pyrosequencing of 16S rRNA gene fragments. We observed that only a relatively small subset of the total community was able to expand to an appreciable distance (more than 2 cm) within 48 h, with the genera Undibacterium, Pseudomonas and Massilia and especially the family Enterobacteriaceae dominating the communities more distant from the point of inoculation. These results suggest that (re-)colonization of open habitats in soil may be dominated by a few rapidly moving species, which may have important consequences for microbial succession.
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, the Netherlands Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, U.S.A.
authors.forename: Alexandra B
authors.initials: AB
authors.lastname: Wolf
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, the Netherlands Department of Plant Health, Institute for Vegetable and Ornamental Crops, Großbeeren/Erfurt e.V., Theodor Echtermeyer Weg 1, D-14979 Großbeeren, Germany.
authors.forename: Max-Bernhard
authors.initials: MB
authors.lastname: Rudnick
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, the Netherlands Department of Soil Quality, Wageningen University, 6700AA Wageningen, the Netherlands.
authors.forename: Wietse
authors.initials: W
authors.lastname: de Boer
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6708 PB Wageningen, the Netherlands Department of Ecological Science, Free University of Amsterdam, 1081 HV Amsterdam, the Netherlands Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, the Netherlands g.a.kowalchuk@uu.nl.
authors.forename: George A
authors.initials: GA
authors.lastname: Kowalchuk
mesh_terms: D017753:Ecosystem; D004755:Enterobacteriaceae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D020459:Genes, rRNA; D064307:Microbiota / Q000235:genetics; D042802:Oxalobacteraceae / Q000235:genetics / Q000378:metabolism*; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D012987:Soil
keywords: Enterobacteriaceae; bacterial diversity; high-throughput tag sequencing; microcosms; motility; succession