| Title | The Broad Habitat Spectrum of the CL500-11 Lineage (Phylum Chloroflexi), a Dominant Bacterioplankton in Oxygenated Hypolimnia of Deep Freshwater Lakes |
| Abstract | CL500-11 (phylum Chloroflexi) is one of the most ubiquitous and abundant bacterioplankton lineages in deep freshwater lakes inhabiting the oxygenated hypolimnion. While metagenomics predicted possible eco-physiological characteristics of this uncultured lineage, no consensus on their ecology has so far been reached, partly because their niche is not clearly understood due to a limited number of quantitative field observations. This study investigated the abundance and distribution of CL500-11 in seven deep perialpine lakes using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). Samples were taken vertically (5-12 depths in each lake) and temporally (in two lakes) at the deepest point of the lakes located in Switzerland, Italy, and Austria with varying depth, trophic state, mixing regime, and water retention time. The results showed a dominance of CL500-11 in all the lakes; their proportion to total prokaryotes ranged from 4.3% (Mondsee) to 24.3% (Lake Garda) and their abundance ranged from 0.65 x 10(5) (Mondsee) to 1.77 x 10(5) (Lake Garda) cells mL(-1). By summarizing available information on CL500-11 occurrence to date, we demonstrated their broad habitat spectrum, ranging from ultra-oligotrophic to mesoeutrophic lakes, while low abundances or complete absence was observed in lakes with shallow depth, low pH, and/or short water retention time (<1 year). Together with available metagenomic and geochemical evidences from literatures, here we reviewed potential substrates supporting growth of CL500-11. Overall, the present study further endorsed ubiquity and quantitative significance of CL500-11 in deep freshwater systems and narrowed the focus on their physiological characteristics and ecological importance. |
| Source | Frontiers in microbiology 9 |
| Keywords | bacterioplanktonCL500-11CARD-FISHperialpine lakesoxygenated hypolimnion |
| Journal | Frontiers in microbiology |
| Editor | Frontiers Research Foundation,, Lausanne, Svizzera |
| Year | 2018 |
| Type | Articolo in rivista |
| DOI | 10.3389/fmicb.2018.02891 |
| Authors | Okazaki, Yusuke; Saicher, Michaels M.; Callieri, Cristiana; Nakano, Shin-ichi |
| Text | 399599 2018 10.3389/fmicb.2018.02891 ISI Web of Science WOS 000451407100001 Scopus 2 s2.0 85057597339 bacterioplankton CL500 11 CARD FISH perialpine lakes oxygenated hypolimnion The Broad Habitat Spectrum of the CL500 11 Lineage Phylum Chloroflexi , a Dominant Bacterioplankton in Oxygenated Hypolimnia of Deep Freshwater Lakes Okazaki, Yusuke; Saicher, Michaels M.; Callieri, Cristiana; Nakano, Shin ichi Center for Ecological Research, Kyoto University, Otsu, Japan; Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan; Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland; CNR IRSA Institute of Water Research, Microbial Ecology Group, Verbania, Italy CL500 11 phylum Chloroflexi is one of the most ubiquitous and abundant bacterioplankton lineages in deep freshwater lakes inhabiting the oxygenated hypolimnion. While metagenomics predicted possible eco physiological characteristics of this uncultured lineage, no consensus on their ecology has so far been reached, partly because their niche is not clearly understood due to a limited number of quantitative field observations. This study investigated the abundance and distribution of CL500 11 in seven deep perialpine lakes using catalyzed reporter deposition fluorescence in situ hybridization CARD FISH . Samples were taken vertically 5 12 depths in each lake and temporally in two lakes at the deepest point of the lakes located in Switzerland, Italy, and Austria with varying depth, trophic state, mixing regime, and water retention time. The results showed a dominance of CL500 11 in all the lakes; their proportion to total prokaryotes ranged from 4.3% Mondsee to 24.3% Lake Garda and their abundance ranged from 0.65 x 10 5 Mondsee to 1.77 x 10 5 Lake Garda cells mL 1 . By summarizing available information on CL500 11 occurrence to date, we demonstrated their broad habitat spectrum, ranging from ultra oligotrophic to mesoeutrophic lakes, while low abundances or complete absence was observed in lakes with shallow depth, low pH, and/or short water retention time <1 year . Together with available metagenomic and geochemical evidences from literatures, here we reviewed potential substrates supporting growth of CL500 11. Overall, the present study further endorsed ubiquity and quantitative significance of CL500 11 in deep freshwater systems and narrowed the focus on their physiological characteristics and ecological importance. 9 Published version Articolo A_2018_IRSA_Frontiers_9_2891.pdf Articolo in rivista Frontiers Research Foundation, 1664 302X Frontiers in microbiology Frontiers in microbiology Front. microbiol. Frontiers in microbiology cristiana.callieri CALLIERI CRISTIANA |
