Common Presence of Phototrophic Gemmatimonadota in Temperate Freshwater Lakes

0546949 - MBÚ 2022 RIV US eng J - Journal Article
Mujakić, Izabela - Andrei, Adrian-Stefan - Shabarova, Tatiana - Kolesár Fecskeová, Lívia - Salcher, Michaela M. - Piwosz, Kasia - Ghai, Rohit - Koblížek, Michal
Common Presence of Phototrophic Gemmatimonadota in Temperate Freshwater Lakes.
mSystems. Roč. 6, č. 2 (2021), č. článku e01241-20. ISSN 2379-5077. E-ISSN 2379-5077
R&D Projects: GA ČR(CZ) GX19-28778X; GA ČR(CZ) GA17-04828S; GA ČR(CZ) GJ20-23718Y; GA ČR(CZ) GA19-23469S; GA ČR(CZ) GX20-12496X
Grant - others:AV ČR(CZ) MSM200961801
Program: Program na podporu mezinárodní spolupráce začínajících výzkumných pracovníků
Institutional support: RVO:61388971 ; RVO:60077344
Keywords : Gemmatimonadota * Gemmatimonadetes * anoxygenic phototrophs * aquatic bacteria * MAGs * metagenome * photosynthesis gene cluster * freshwater ecology * card-fish
OECD category: Microbiology; Microbiology (BC-A)
Impact factor: 7.328, year: 2021
Method of publishing: Open access
https://journals.asm.org/doi/10.1128/mSystems.01241-20

Members of the bacterial phylum Gemmatimonadota are ubiquitous in most natural environments and represent one of the top 10 most abundant bacterial phyla in soil. Sequences affiliated with Gemmatimonadota were also reported from diverse aquatic habitats, however, it remains unknown whether they are native organisms or represent bacteria passively transported from sediment or soil. To address this question, we analyzed metagenomes constructed from five freshwater lakes in central Europe. Based on the 16S rRNA gene frequency, Gemmatimonadota represented from 0.02 to 0.6% of all bacteria in the epilimnion and between 0.1 and 1% in the hypolimnion. These proportions were independently confirmed using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). Some cells in the epilimnion were attached to diatoms (Fragilaria sp.) or cyanobacteria (Microcystis sp.), which suggests a close association with phytoplankton. In addition, we reconstructed 45 metagenome-assembled genomes (MAGs) related to Gemmatimonadota. They represent several novel lineages, which persist in the studied lakes during the seasons. Three lineages contained photosynthesis gene clusters. One of these lineages was related to Gemmatimonas phototrophica and represented the majority of Gemmatimonadota retrieved from the lakes' epilimnion. The other two lineages came from hypolimnion and probably represented novel photoheterotrophic genera. None of these phototrophic MAGs contained genes for carbon fixation. Since most of the identified MAGs were present during the whole year and cells associated with phytoplankton were observed, we conclude that they represent truly limnic Gemmatimonadota distinct from the previously described species isolated from soils or sediments.
Permanent Link: http://hdl.handle.net/11104/0323331