Ursu Lake is located in the Middle Miocene salt deposit of Central Romania. It is stratified, and the water column has three distinct water masses: an upper freshwater-to-moderately saline stratum (0-3 m), an intermediate stratum exhibiting a steep halocline (3-3.5 m), and a lower hypersaline stratum (4 m and below) that is euxinic (i.e. anoxic and sulphidic). Recent studies have characterized the lake's microbial taxonomy and given rise to intriguing ecological questions. Here, we explore whether the communities are dynamic or stable in relation to taxonomic composition, geochemistry, biophysics, and ecophysiological functions during the annual cycle. We found: (i) seasonally fluctuating, light-dependent communities in the upper layer (≥0.987-0.990 water-activity), a stable but phylogenetically diverse population of heterotrophs in the hypersaline stratum (water activities down to 0.762) and a persistent plate of green sulphur bacteria that connects these two (0.958-0.956 water activity) at 3-3.5 to 4 m; (ii) communities that might be involved in carbon- and sulphur-cycling between and within the lake's three main water masses; (iii) uncultured lineages including Acetothermia (OP1), Cloacimonetes (WWE1), Marinimicrobia (SAR406), Omnitrophicaeota (OP3), Parcubacteria (OD1) and other Candidate Phyla Radiation bacteria, and SR1 in the hypersaline stratum (likely involved in the anaerobic steps of carbon- and sulphur-cycling); and (iv) that species richness and habitat stability are associated with high redox-potentials. Ursu Lake has a unique and complex ecology, at the same time exhibiting dynamic fluctuations and stability, and can be used as a modern analogue for ancient euxinic water bodies and comparator system for other stratified hypersaline systems.

Biological Research Center Jibou 16 Wesselenyi Miklos Str 455200 Jibou Romania

Department of Aquatic Microbial Ecology Institute of Hydrobiology Biology Centre CAS Na Sádkách 702 7 370 05 České Budějovice Czech Republic

Department of Molecular Biology and Biotechnology Faculty of Biology and Geology Babeş Bolyai University 5 7 Clinicilor Str 400006 Cluj Napoca Romania

Department of Physical and Technical Geography Faculty of Geography Babeş Bolyai University 5 7 Clinicilor Str 400006 Cluj Napoca Romania

Department of Taxonomy and Ecology Faculty of Biology and Geology Babeş Bolyai University 5 7 Clinicilor Str 400006 Cluj Napoca Romania

Faculty of Environmental Science and Engineering Babeş Bolyai University 30 Fantanele Str 400294 Cluj Napoca Romania

INCDO INOE 2000 Research Institute for Analytical Instrumentation 67 Donath Str 400293 Cluj Napoca Romania

Institute for Global Food Security School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens Belfast BT9 7BL UK

Institute for Interdisciplinary Research in Bio Nano Sciences 42 A Treboniu Laurian Str Babeş Bolyai University 400271 Cluj Napoca Romania

National Institute of Research and Development for Biological Sciences Institute of Biological Research 48 Republicii Str 400015 Cluj Napoca Romania

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Alexe, M., Șerban, G., Baricz, A., Andrei, A.-Ș., Cristea, A., Battes, K., et al. (2018) Limnology and plankton diversity of salt lakes from Transylvanian Basin (Romania): a review. J Limnol 77: 17-34.

Alves, F.D.L., Stevenson, A., Baxter, E., Gillion, J.L., Hejazi, F., Hayes, S., et al. (2015) Concomitant osmotic and chaotropicity-induced stresses in Aspergillus wentii: compatible solutes determine the biotic window. Curr Gen 61: 457-477.

Andrei, A.-Ş., Baricz, A., Robeson, M.S., Păuşan, M.R., Tămaş, T., Chiriac, C., et al. (2017) Hypersaline sapropels act as hotspots for microbial dark matter. Sci Rep 7: 6150.

Andrei, A.-Ş., Robeson, M.S., Baricz, A., Coman, C., Muntean, V., Ionescu, A., et al. (2015) Contrasting taxonomic stratification of microbial communities in two hypersaline meromictic lakes. ISME J 9: 2642-2656.

Aßhauer, K.P., Wemheuer, B., Daniel, R., and Meinicke, P. (2015) Tax4Fun: predicting functional profiles from metagenomic 16S rRNA data. Bioinformatics 31: 2882-2884.

Baatar, B., Chiang, P.W., Rogozin, D.Y., Wu, Y.T., Tseng, C.H., Yang, C.Y., et al. (2016) Bacterial communities of three saline meromictic lakes in Central Asia. PloS One 11: e0150847.

Barberán, A., and Casamayor, E.O. (2011) Euxinic freshwater hypolimnia promote bacterial endemicity in continental areas. Microb Ecol 61: 465-472.

Baricz, A., Coman, C., Andrei, A.-Ş., Muntean, V., Keresztes, Z.G., Păuşan, M., et al. (2014) Spatial and temporal distribution of archaeal diversity in meromictic, hypersaline Ocnei Lake (Transylvanian Basin, Romania). Extremophiles 18: 399-413.

Baricz, A., Cristea, A., Muntean, V., Teodosiu, G., Andrei, A.-Ş., Molnár, I., et al. (2015) Culturable diversity of aerobic halophilic archaea (Fam. Halobacteriaceae) from hypersaline, meromictic Transylvanian lakes. Extremophiles 19: 525-537.

Boehrer, B., and Schultze, M. (2008) Stratification of lakes. Rev Geophys 46: RG2005.

Boehrer, B., von Rohden, C., and Schultze, M. (2017) Physical features of meromictic lakes: stratification and circulation. In Ecology of Meromictic Lakes, Gulati, R.D., Zadereev, E.S., and Degermendzhi, A.G. (eds). Switzerland: Springer International Publishing, pp. 15-34.

Borin, S., Mapelli, F., Rolli, E., Song, B., Tobias, C., Schmid, M.C., et al. (2013) Anammox bacterial populations in deep marine hypersaline gradient systems. Extremophiles 17: 289-299.

Bower, C.E., and Holm-Hansen, T. (1980) A salicylate-hypochlorite method for determining ammonia in seawater. Can J Fish Aquat Sci 37: 794-798.

Brown, C.T., Hug, L.A., Thomas, B.C., Sharon, I., Castelle, C.J., Singh, A., et al. (2015) Unusual biology across a group comprising more than 15% of domain Bacteria. Nature 523: 208-211.

Callieri, C., Amalfitano, S., Corno, G., Di Cesare, A., Bertoni, R., and Eckert, E.M. (2017) The microbiome associated with two Synechococcus ribotypes at different levels of ecological interaction. J Phycol 53: 1151-1158.

Caporaso, J.G., Kuczynski, J., Stombaugh, J., Bittinger, K., Bushman, F.D., Costello, E.K., et al. (2010) QIIME allows analysis of high-throughput community sequencing data. Nat Methods 7: 335-336.

Castelle, C.J., and Banfield, J.F. (2018) Major new microbial groups expand diversity and alter our understanding of the tree of life. Cell 172: 1181-1197.

Castelle, C.J., Brown, C.T., Thomas, B.C., Williams, K.H., and Banfield, J.F. (2017) Unusual respiratory capacity and nitrogen metabolism in a Parcubacterium (OD1) of the candidate phyla radiation. Sci Rep 7: 40101.

Clarke, K.R. (1993) Non-parametric multivariate analyses of changes in community structure. Aust J Ecol 18: 117-143.

Crits-Christoph, A., Gelsinger, D.R., Ma, B., Wierzchos, J., Ravel, J., Davila, A., et al. (2016) Functional interactions of archaea, bacteria and viruses in a hypersaline endolithic community. Environ Microbiol 18: 2064-2077.

Cole, J.R., Wang, Q., Fish, J.A., Chai, B., McGarrell, D.M., Sun, Y., et al. (2014) Ribosomal database project: data and tools for high throughput rRNA analysis. Nucleic Acids Res 42: 633-642.

Daffochino, D., Borin, S., Brusa, T., Brusetti, L., van der Wielen, P.W.J.J., Bolhuis, H., et al. (2006) Stratified prokaryote network in the oxic-anoxic transition of a deep-sea halocline. Nature 440: 203-207.

Damsté, J.S.S., Schouten, S., and van Duin, A.C. (2001) Isorenieratene derivatives in sediments: possible controls on their distribution. Geochim Cosmochim Acta 65: 1557-1571.

Degermendzhy, A.G., Zadereev, E.S., Rogozin, D.Y., Prokopkin, I.G., Barkhatov, Y.V., Tolomeev, A.P., et al. (2010) Vertical stratification of physical, chemical and biological components in two saline lakes Shira and Shunet (South Siberia, Russia). Aquat Ecol 244: 619-632.

Delmont, T.O., Eren, A.M., Vineis, J.H., and Post, A.F. (2015) Genome reconstructions indicate the partitioning of ecological functions inside a phytoplankton bloom in the Amundsen Sea, Antarctica. Front Microbiol 6: 1090.

DeSantis, T.Z., Hugenholtz, P., Larsen, N., Rojas, M., Brodie, L.E., Keller, K., et al. (2006) Greengenes, a chimera-checked 16S rRNA gene database and workbench compatible with ARB. Appl Environ Microbiol 72: 5069-5072.

Dimitriu, P.A., Pinkart, H.C., Peyton, B.M., and Mormile, M.R. (2008) Spatial and temporal patterns in the microbial diversity of a meromictic soda lake in Washington state. Appl Environ Microbiol 74: 4877-4888.

Edgar, R.C. (2013) UPARSE: highly accurate OTU sequences from microbial amplicon reads. Nat Methods 10: 996-998.

Fox-Powell, M.G., Hallsworth, J.E., Cousins, C.R., and Cockell, C.S. (2016) Ionic strength is a barrier to the habitability of Mars. Astrobiology 16: 427-442.

Galand, P.E., Casamayor, E.O., Kirchman, D.L., and Lovejoy, C. (2009) Ecology of the rare microbial biosphere of the Arctic Ocean. Proc Natl Acad Sci U S A 106: 22427-22432.

Gies, E.A., Konwar, K.M., Beatty, J.T., and Hallam, S.J. (2014) Illuminating microbial dark matter in meromictic Sakinaw Lake. Appl Environ Microbiol 80: 6807-6818.

Glöckner, F.O., Kube, M., Bauer, M., Teeling, H., Lombardot, T., Ludwig, W., et al. (2003) Complete genome sequence of the marine planctomycete Pirellula sp. strain 1. Proc Natl Acad Sci U S A 100: 8298-8303.

Glöckner, J., Kube, M., Shrestha, P.M., Weber, M., Glöckner, F.O., Reinhardt, R., and Liesack, W. (2010) Phylogenetic diversity and metagenomics of candidate division OP3. Environ Microbiol 12: 1218-1229.

Guyoneaud, R., Borrego, C.M., Martinez-Planells, A., Buitenhuis, E.T., and Garcia-Gil, L.J. (2001) Light responses in the green sulfur bacterium Prosthecochloris aestuarii: changes in prosthecae length, ultrastructure, and antenna pigment composition. Arch Microbiol 176: 278-284.

Hallsworth, J.E., Yakimov, M.M., Golyshin, P.N., Gillion, J.L., D'Auria, G., de Lima Alves, F., et al. (2007) Limits of life in MgCl2-containing environments: chaotropicity defines the window. Environ Microbiol 9: 801-813.

Hallsworth, J.E. (2018) Stress-free microbes lack vitality. Fungal Biol 122: 379-385.

Hallsworth, J.E. (2019) Microbial unknowns at the saline limits for life. Nat Ecol Evol 3: 1503-1504.

Hamilton, T.L., Bovee, R.J., Sattin, S.R., Mohr, W., Gilhooly, W.P., III, Lyons, T.W., et al. (2016) Carbon and sulfur cycling below the chemocline in a meromictic lake and the identification of a novel taxonomic lineage in the FCB superphylum, Candidatus Aegiribacteria. Front Microbiol 7: 598.

Hammer, U.T. (1986) Saline Lake Ecosystems of the World, Vol. 59. Dordrecht, Netherlands: Springer Science and Business Media.

Hao, L., Mcllroy, S.J., Kirkegaard, R.H., Karst, S.M., Fernando, W.E.Y., Aslan, H., et al. (2018) Novel prosthecate bacteria from the candidate phylum Acetothermia. ISME J 12: 2225-2237.

Harris, J.K., Kelley, S.T., and Pace, N.R. (2004) New perspective on uncultured bacterial phylogenetic division OP11. Appl Environ Microbiol 70: 845-849.

Harter, T., Watanabe, N., Li, X., Atwill, E.R., and Samuels, W. (2014) Microbial groundwater sampling protocol for fecal-rich environments. Groundwater 52: 126-136.

Hu, P., Tom, L., Singh, A., Thomas, B.C., Baker, B.J., Piceno, Y.M., et al. (2016) Genome resolved metagenomic analysis reveals roles for candidate phyla and other microbial community members in biogeochemical transformations in oil reservoirs. MBio 7: e01669-e01615.

Hugoni, M., Taib, N., Debroas, D., Domaizon, I., Jouan Dufournel, I., Bronner, G., et al. (2013) Structure of the rare archaeal biosphere and seasonal dynamics of active ecotypes in surface coastal waters. Proc Natl Acad Sci USA 110: 6004-6009.

Ionescu, A., Baciu, C., Kis, B.M., and Sauer, P.E. (2017) Evaluation of dissolved light hydrocarbons in different geological settings in Romania. Chem Geol 469: 230-245.

Jonkers, H.M., Ludwig, R., de Wit, R., Pringault, O.G., Muyzer, G., Niemann, H., et al. (2003) Structural and functional analysis of a microbial mat ecosystem from a unique permanent hypersaline inland lake: ‘La Salada de Chiprana’ (NE Spain). FEMS Microbiol Ecol 44: 175-189.

Keresztes, Z.G., Felföldi, T., Somogyi, B., Székely, G., Dragoş, N., Márialigeti, K., et al. (2012) First record of picophytoplankton diversity in Central European hypersaline lakes. Extremophiles 16: 759-769.

Kimura, M.A. (1980) A simple method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences. J Mol Evol 16: 111-120.

Klepac-Ceraj, V., Hayes, C.A., Gilhooly, W.P., Lyons, T.W., Kolter, R., and Pearson, A. (2012) Microbial diversity under extreme euxinia: Mahoney Lake, Canada. Geobiology 10: 223-235.

Knight, R., Vrbanac, A., Taylor, B.C., Aksenov, A., Callewaert, C., Debelius, J., et al. (2018) Best practices for analysing microbiomes. Nat Rev Microbiol 16: 410-422.

Kumar, S., Stecher, G., and Tamura, K. (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Mol Biol Evol 33: 1870-1874.

La Cono, V., Bortoluzzi, G., Messina, E., La Spada, G., Smedile, F., Giuliano, L., et al. (2019) The discovery of Lake Hephaestus, the youngest athalassohaline deep-sea formation on Earth. Sci Rep 9: 1679.

Larson, C.A., and Belovsky, G.E. (2013) Salinity and nutrients influence species richness and evenness of phytoplankton communities in microcosm experiments from Great Salt Lake, Utah, USA. J Plankton Res 35: 1154-1166.

Lauro, F.M., DeMaere, M.Z., Yau, S., Brown, M.V., Ng, C., Wilkins, D., et al. (2011) An integrative study of a meromictic lake ecosystem in Antarctica. ISME J 5: 879-795.

Laybourn-Parry, J., and Bell, E.M. (2014) Ace Lake: three decades of research on a meromictic, Antarctic lake. Polar Biol 37: 1685-1699.

Lee, C.J.D., McMullan, P.E., O'Kane, C.J., Stevenson, A., Santos, I.C., Roy, C., et al. (2018) NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats. FEMS Microbiol Rev 42: 672-693.

Lehours, A.C., Bardot, C., Thenot, A., Debroas, D., and Fonty, G. (2005) Anaerobic microbial communities in Lake Pavin, a unique meromictic lake in France. Appl Environ Microbiol 71: 7389-7400.

Leinonen, R., Akhtar, R., Birney, E., Bower, L., Cerdeno-Tárraga, A., Cheng, Y., et al. (2011) The European nucleotide archive. Nucleic Acids Res 39: D28-D31.

Limam, R.D., Chouari, R., Mazéas, L., Wu, T.D., Li, T., Grossin-Debattista, J., et al. (2014) Members of the uncultured bacterial candidate division WWE1 are implicated in anaerobic digestion of cellulose. Microbiol Open 3: 157-167.

Llorens-Marès, T., Triadó-Margarit, X., Borrego, C.M., Dupont, C.L., and Casamayor, E.O. (2016) High bacterial diversity and phylogenetic novelty in dark euxinic freshwaters analyzed by 16S tag community profiling. Microb Ecol 71: 566-574.

Lynch, M.D., and Neufeld, J.D. (2015) Ecology and exploration of the rare biosphere. Nat Rev Microbiol 13: 217-229.

Máthé, I., Borsodi, A.K., Tóth, E.M., Felföldi, T., Jurecska, L., Krett, G., et al. (2014) Vertical physico-chemical gradients with distinct microbial communities in the hypersaline and heliothermal Lake Ursu (Sovata, Romania). Extremophiles 18: 501-514.

Merlino, G., Barozzi, A., Michoud, G., Ngugi, D.K., and Daffonchio, D. (2018) Microbial ecology of deep-sea hypersaline anoxic basins. FEMS Microbiol Ecol 94: fiy085.

Meyer, K.M., and Kump, L.R. (2008) Oceanic euxinia in Earth history: Causes and consequences. Ann. Rev Earth Planet Sci 36: 251-288.

Meyerhof, M.S., Wilson, J.M., Dawson, M.N., and Beman, M.J. (2016) Microbial community diversity, structure and assembly across oxygen gradients in meromictic marine lakes, Palau. Environ Microbiol. 18: 4907-4919.

Nelson, C.E., and Carlson, C.A. (2012) Tracking differential incorporation of dissolved organic carbon types among diverse lineages of Sargasso Sea bacterioplankton. Environ Microbiol 14: 1500-1516.

Nelson, W.C., and Stegen, J.C. (2015) The reduced genomes of Parcubacteria (OD1) contain signatures of a symbiotic lifestyle. Front Microbiol 6: 713.

Nigro, L.M., Hyde, A.S., MacGregor, B.J., and Teske, A. (2016) Phylogeography, salinity adaptations and metabolic potential of the candidate division KB1 bacteria based on a partial single cell genome. Front Microbiol 7: 1266.

Nobu, M.K., Dodsworth, J.A., Murugapiran, S.K., Rinke, C., Gies, E.A., Webster, G., et al. (2016) Phylogeny and physiology of candidate phylum “Atribacteria” (OP9/JS1) inferred from cultivation-independent genomics. ISME J 10: 273-286.

Oren, A. (2011) Thermodynamic limits to microbial life at high salt concentrations. Environ Microbiol 13: 1908-1923.

Orsi, W.D., Smith, J.M., Liu, S., Liu, Z., Sakamoto, C.M., Wilken, S., et al. (2016) Diverse, uncultivated bacteria and archaea underlying the cycling of dissolved protein in the ocean. ISME J 10: 2158-2173.

Paul, D., Kumbhare, S.V., Mhatre, S.S., Chowdhury, S.P., Shetty, S.A., Marathe, N.P., et al. (2016) Exploration of microbial diversity and community structure of Lonar Lake: the only hypersaline meteorite crater lake within basalt rock. Front Microbiol 6: 1553.

Pedrós-Alió, C. (2012) The rare bacterial biosphere. Ann Rev Mar Sci 4: 449-466.

Peryt, T.M., Peryt, D., and Poberezhskyy, A.V. (2008) Badenian (Middle Miocene) laminated gypsum facies from Kudryntsi on Zbruch River (West Ukraine). In Recent Problems of Lithology and Minerogenesis of Sedimentary Basins of Ukraine and Adjacent Territories, Gozhyk, P.F., et al. (eds). Ukraine: Institute of Geological Sciences NAS, pp. 140-145.

Peura, S., Eiler, A., Bertilsson, S., Nykänen, H., Tiirola, M., and Jones, R.I. (2012) Distinct and diverse anaerobic bacterial communities in boreal lakes dominated by candidate division OD1. ISME J 6: 1640-1652.

Prairie, J.C., Ziervogel, K., Camassa, R., McLaughlin, R.M., White, B.L., Dewald, C., and Arnosti, C. (2015) Delayed settling of marine snow: effects of density gradient and particle properties and implications for carbon cycling. Mar Chem 175: 28-38.

Pruesse, E., Peplies, J., and Glöckner, F.O. (2012) SINA: accurate high-throughput multiple sequence alignment of ribosomal RNA genes. Bioinformatics 28: 1823-1829.

Quast, C., Pruesse, E., Yilmaz, P., Gerken, J., Schweer, T., Yarza, P., et al. (2013) The SILVA ribosomal RNA gene database project: improved data processing and web-based tools. Nucleic Acids Res 41: D590-D596.

Raup, O.B. (1970) Brine mixing: an additional mechanism for formation of basin evaporites. Am Assoc Pet Geol Bull 54: 2246-2259.

Rinke, C., Schwientek, P., Sczyrba, A., Ivanova, N.N., Anderson, I.J., Cheng, J.F., et al. (2013) Insights into the phylogeny and coding potential of microbial dark matter. Nature 499: 431-437.

Rogozin, D.Y., Trusova, M.Y., Khromechek, E.B., and Degermendzhy, A.G. (2010) Microbial community of the chemocline of the meromictic Lake Shunet (Khakassia, Russia) during summer stratification. Microbiology 79: 253-261.

Saitou, N., and Nei, M. (1987) The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4: 406-425.

Schneider, D., Arp, G., Reimer, A., Reitner, J., and Daniel, R. (2013) Phylogenetic analysis of a microbialite-forming microbial mat from a hypersaline lake of the Kiritimati atoll, Central Pacific. PLoS One 8: e66662.

Stevenson, A., Cray, J.A., Williams, J.P., Santos, R., Sahay, R., Neuenkirchen, N., et al. (2015) Is there a common water-activity limit for the three domains of life? ISME J 9: 1333-1351.

Stevenson, A., Hamill, P.G., O'Kane, C.J., Kminek, G., Rummel, J.D., Voytek, M.A., et al. (2017) Aspergillus penicillioides differentiation and cell division at 0.585 water activity. Environ Microbiol 19: 687-697.

Teeling, H., Fuchs, B.M., Bennke, C.M., Kruger, K., Chafee, M., Kappelmann, L., et al. (2016) Recurring patterns in bacterioplankton dynamics during coastal spring algae blooms. Elife 5: e11888.

Trüper, H.G., and Schlegel, H.G. (1964) Sulfur metabolism in Thiorhodaceae. I. Quantitative measurements on growing cells of Chromatium okenii. Antonie Van Leeuwenhoek 30: 225-238.

Thorpe, S.A. (1969) Experiments on the stability of stratified shear flows. Radio Sci 4: 1327-1331.

Uritskiy, G., and Di Ruggiero, J. (2019) Applying genome-resolved metagenomics to de-convolute the halophilic microbiome. Genes 10: 220.

Viver, T., Orellana, L.H., Díaz, S., Urdiain, M., Ramos-Barbero, M.D., González-Pastor, J.E., et al. (2019) Predominance of deterministic microbial community dynamics in salterns exposed to different light intensities. Environ Microbiol 21: 4300-4315.

Wetzel, R.G., and Likens, G.E. (eds). (2000) Limnological Analyses, 3rd ed. New York: Springer Verlag.

Woebken, D., Teeling, H., Wecker, P., Dimitriu, A., Kostandinov, I., Delong, E.F., et al. (2007) Fosmids of novel marine Planctomycetes from the Namibian and Oregon coast upwelling systems and their cross-comparison with planctomycete genomes. ISME J 1: 419-435.

Wrighton, K.C., Castelle, C.J., Wilkins, M.J., Hug, L.A., Sharon, I., Thomas, B.C., et al. (2014) Metabolic interdependencies between phylogenetically novel fermenters and respiratory organisms in an unconfined aquifer. ISME J 8: 1452-1463.

Wu, Y.T., Yang, C.Y., Chiang, P.W., Tseng, C.H., Chiu, H.H., Saeed, I., et al. (2018) Comprehensive insights into composition, metabolic potentials, and interactions among archaeal, bacterial, and viral assemblages in meromictic Lake Shunet in Siberia. Front Microbiol 9: 1763.

Yakimov, M.M., La Cono, V., Slepak, V.Z., La Spada, G., Arcadi, E., Messina, E., et al. (2013) Microbial life in the Lake Medeé, the largest deep-sea salt-saturated formation. Sci Rep 3: 3554.

Yakimov, M.M., La Cono, V., Spada, G.L., Bortoluzzi, G., Messina, E., Smedile, F., et al. (2015) Microbial community of the deep-sea brine Lake Kryos seawater-brine interface is active below the chaotropicity limit of life as revealed by recovery of mRNA. Environ Microbiol 17: 364-382.

Yau, S., Lauro, F.M., Williams, T.J., Demaere, M.Z., Brown, M.V., Rich, J., et al. (2013) Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake. ISME J 7: 1944-1961.

Yeoh, Y.K., Sekiguchi, Y., Parks, D.H., and Hugenholtz, P. (2016) Comparative genomics of candidate phylum TM6 suggests that parasitism is widespread and ancestral in this lineage. Mol Biol Evol 33: 915-927.

Yilmaz, P., Parfrey, L.W., Yarza, P., Gerken, J., Pruesse, E., Quast, C., et al. (2014) The SILVA and “All-species Living Tree Project (LTP)” taxonomic frameworks. Nucleic Acids Res 42: 643-648.

Zadereev, E.S., Gulati, R.D., and Camacho, A. (2017) Biological and ecological features, trophic structure and energy flow in meromictic lakes. In Ecology of Meromictic Lakes, Gulati, R.D., Zadereev, E.S., and Degermendzhi, A.G. (eds). Switzerland: Springer International Publishing, pp. 61-86.

Ecogenomics sheds light on diverse lifestyle strategies in freshwater CPR