Complete ecological isolation and cryptic diversity in Polynucleobacter bacteria not resolved by 16S rRNA gene sequences.

0459789 - BC 2017 RIV GB eng J - Journal Article
Hahn, M.W. - Jezberová, Jitka - Koll, U. - Saueressig-Beck, T. - Schmidt, J.
Complete ecological isolation and cryptic diversity in Polynucleobacter bacteria not resolved by 16S rRNA gene sequences.
The ISME Journal. Roč. 10, č. 7 (2016), s. 1642-1655. ISSN 1751-7362. E-ISSN 1751-7370
Institutional support: RVO:60077344
Keywords : fresh-water habitats * microbial species delineation * alteromonas-macleodii * community structure * genome sequence * organic-matter
Subject RIV: EE - Microbiology, Virology
Impact factor: 9.664, year: 2016

Transplantation experiments and genome comparisons were used to determine if lineages of planktonic Polynucleobacter almost indistinguishable by their 16S ribosomal RNA (rRNA) sequences differ distinctively in their ecophysiological and genomic traits. The results of three transplantation experiments differing in complexity of biotic interactions revealed complete ecological isolation between some of the lineages. This pattern fits well to the previously detected environmental distribution of lineages along chemical gradients, as well as to differences in gene content putatively providing adaptation to chemically distinct habitats. Patterns of distribution of iron transporter genes across 209 Polynucleobacter strains obtained from freshwater systems and representing a broad pH spectrum further emphasize differences in habitat-specific adaptations. Genome comparisons of six strains sharing >= 99% 16S rRNA similarities suggested that each strain represents a distinct species. Comparison of sequence diversity among genomes with sequence diversity among 240 cultivated Polynucleobacter strains indicated a large cryptic species complex not resolvable by 16S rRNA sequences. The revealed ecological isolation and cryptic diversity in Polynucleobacter bacteria is crucial in the interpretation of diversity studies on freshwater bacterioplankton based on ribosomal sequences.
Permanent Link: http://hdl.handle.net/11104/0259963