Molecular analysis of intestinal microbiota of rainbow trout (Oncorhynchus mykiss).
The aim of this study was to evaluate different molecular tools based on the 16S rRNA gene, internal transcribed spacer, and the rpoB gene to examine the bacterial populations present in juvenile rainbow trout intestines. DNA was extracted from both pooled intestinal samples and bacterial strains. Genes were PCR-amplified and analysed using both temporal temperature gradient gel electrophoresis (TTGE) and restriction fragment length polymorphism methods. Because of the high cultivability of the samples, representative bacterial strains were retrieved and we compared the profiles obtained from isolated bacteria with the profile of total bacteria from intestinal contents. Direct analysis based on rpoB-TTGE revealed a simple bacterial composition with two to four bands per sample, while the 16S rRNA gene-TTGE showed multiple bands and comigration for a few species. Sequencing of the 16S rRNA gene- and rpoB-TTGE bands revealed that the intestinal microbiota was dominated by Lactococcus lactis, Citrobacter gillenii, Kluyvera intermedia, Obesumbacterium proteus, and Shewanella marinus. In contrast to 16S rRNA gene-TTGE, rpoB-TTGE profiles derived from bacterial strains produced one band per species. Because the single-copy state of rpoB leads to a single band in TTGE, the rpoB gene is a promising molecular marker for investigating the bacterial community of the rainbow trout intestinal microbiota.
Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.
Paola
P
Navarrete
Fabien
F
Magne
Pamela
P
Mardones
Macarena
M
Riveros
Rafael
R
Opazo
Antonia
A
Suau
Philippe
P
Pochart
Jaime
J
Romero
D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D001426:Bacterial Proteins / Q000235:genetics; D015169:Colony Count, Microbial / Q000662:veterinary; D004269:DNA, Bacterial / Q000235:genetics*; D021901:DNA, Intergenic / Q000235:genetics; D004587:Electrophoresis, Agar Gel / Q000379:methods; D005798:Genes, Bacterial; D005819:Genetic Markers; D007422:Intestines / Q000382:microbiology*; D017686:Oncorhynchus mykiss / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D021901:DNA, Intergenic; D005819:Genetic Markers; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S