title: Genetic difference but functional similarity among fish gut bacterial communities through molecular and biochemical fingerprints.
abstract: Considering the major involvement of gut microflora in the digestive function of various macro-organisms, bacterial communities inhabiting fish guts may be the main actors of organic matter degradation by fish. Nevertheless, the extent and the sources of variability in the degradation potential of gut bacterial communities are largely overlooked. Using Biolog Ecoplate™ and denaturing gradient gel electrophoresis (DGGE), we explored functional (i.e. the ability to degrade organic matter) and genetic (i.e. identification of DGGE banding patterns) diversity of fish gut bacterial communities, respectively. Gut bacterial communities were extracted from fish species characterized by different diets sampled along a salinity gradient in the Patos-Mirim lagoons complex (Brazil). We found that functional diversity was surprisingly unrelated to genetic diversity of gut bacterial communities. Functional diversity was not affected by the sampling site but by fish species and diet, whereas genetic diversity was significantly influenced by all three factors. Overall, the functional diversity was consistently high across fish individuals and species, suggesting a wide functional niche breadth and a high potential of organic matter degradation. We conclude that fish gut bacterial communities may strongly contribute to nutrient cycling regardless of their genetic diversity and environment.
authors.affiliation: UMR 5119 CNRS-UM2-UM1-IRD-Ifremer Ecologie des systèmes marins côtiers, Université Montpellier 2, Montpellier, France. maud.mouchet@gmail.com
authors.forename: Maud A
authors.initials: MA
authors.lastname: Mouchet
authors.forename: Corinne
authors.initials: C
authors.lastname: Bouvier
authors.forename: Thierry
authors.initials: T
authors.lastname: Bouvier
authors.forename: Marc
authors.initials: M
authors.lastname: Troussellier
authors.forename: Arthur
authors.initials: A
authors.lastname: Escalas
authors.forename: David
authors.initials: D
authors.lastname: Mouillot
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics*; D044822:Biodiversity; D001938:Brazil; D016172:DNA Fingerprinting; D005399:Fishes / Q000382:microbiology*; D005766:Gastrointestinal Contents / Q000382:microbiology*; D014644:Genetic Variation; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S