Genotypic Distribution of a Specialist Model Microorganism, Methanosaeta, along an Estuarine Gradient: Does Metabolic Restriction Limit Niche Differentiation Potential?

• Published in: Microbial ecology Vol. 63; no. 4; pp. 856 - 864
• Main Authors: Carbonero, Franck, Oakley, Brian B., Hawkins, Robert J., Purdy, Kevin J.
• Format: Journal Article
• Language: English
• Published: New York Springer Science + Business Media 01.05.2012; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Biological and medical sciences; Biomedical and Life Sciences; Brackish; Cloning, Molecular; Community structure; Deltaproteobacteria - genetics; Deltaproteobacteria - metabolism; Denaturing Gradient Gel Electrophoresis; Deoxyribonucleic acid; Desulfobulbus; Distribution patterns; DNA; DNA, Archaeal - analysis; Ecology; Ecosystem; Environmental factors; ENVIRONMENTAL MICROBIOLOGY; Estuaries; Fundamental and applied biological sciences. Psychology; Gene Library; Genotype; Genotypes; Geoecology/Natural Processes; Life Sciences; Mantels; Metabolism; Methanosaeta; Methanosarcinales - classification; Methanosarcinales - genetics; Methanosarcinales - isolation & purification; Methanosarcinales - metabolism; Microbial Ecology; Microbiology; Molecular Sequence Data; Nature Conservation; Niches; Polymerase chain reaction; Product category rules; RNA; RNA, Archaeal - analysis; Sediments; Sequence Analysis, DNA; Spatial distribution; Water Quality/Water Pollution; ANE, British Isles, England, Essex, Colne Estuary; British Isles; ANE, British Isles, England, Essex; Clone Library; Methanosarcina; Partial Mantel Test; Methanosaeta; Dissimilarity Matrice; Brackish water environment; Ecological niche; Estuaries; Ecology; Models; Microorganism; Differentiation
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-011-9993-6

A reductionist ecological approach of using a model genus was adopted in order to understand how microbial community structure is driven by metabolic properties. The distribution along an estuarine gradient of the highly specialised genus Methanosaeta was investigated and compared to the previously determined distribution of the more metabolically flexible Desulfobulbus. Methanosaeta genotypic distribution along the Colne estuary (Essex, UK) was determined by DNA- and RNA-based denaturing gradient gel electrophoresis and 16S rRNA gene sequence analyses. Methanosaeta distribution was monotonie, with a consistently diverse community and no apparent niche partitioning either in DNA or RNA analyses. This distribution pattern contrasts markedly with the previously described niche partitioning and sympatric differentiation of the model generalist, Desulfobulbus. To explain this difference, it is hypothesised that Methanosaeta's strict metabolic needs limit its adaptation potential, thus populations do not partition into spatially distinct groups and so do not appear to be constrained by gross environmental factors such as salinity. Thus, at least for these two model genera, it appears that metabolic flexibility may be an important factor in spatial distribution and this may be applicable to other microbes.