Contrasting taxonomic stratification of microbial communities in two hypersaline meromictic lakes ADRIAN-ȘTEFAN ANDREI 1,2ⱡ, MICHAEL S. ROBESON II 3ⱡ, ANDREEA BARICZ 2,4, CRISTIAN COMAN 2,4, VASILE MUNTEAN 2, ARTUR IONESCU 5, GIUSEPPE ETIOPE 5,6, MIRCEA ALEXE 7, COSMIN IONEL SICORA 8, MIRCEA PODAR 3,9 and HORIA LEONARD BANCIU 1,2,* 1 Institute for Interdisciplinary Research in Bio-Nano-Sciences, Babeş-Bolyai University, Cluj-Napoca, Romania; 2 Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, Cluj-Napoca, Romania; 3 Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA; 4 National Institute of Research and Development for Biological Sciences (NIRDBS), Institute of Biological Research, Cluj-Napoca, Romania; 5 Faculty of Environmental Science and Engineering, Babeş-Bolyai University, Cluj-Napoca, Romania; 6 Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma 2, Italy ; 7 Faculty of Geography, Babeş-Bolyai University, Cluj-Napoca, Romania; 8 Biological Research Center, Jibou, Romania; 9 Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA; *Corresponding author: Department of Molecular Biology and Biotechnology, Babeş-Bolyai University, 5-7 Clinicilor Str., 400006 Cluj-Napoca, Romania. Telephone: +40-264431691; fax: +40-264431858. E- mail: horia.banciu@ubbcluj.ro; ⱡ "These authors contributed equally to this work"
Figure 1. Algae cell numbers per ml, in Fara Fund Lake, as estimated by epifluorescence microscopy. The sampling depths are represented on the abscissa. The error bars represent standard deviations. 2.01E+05 Number of algae per ml 1.51E+05 1.01E+05 5.10E+04 1.00E+03 0.5 m 2 m 3 m 11 m
Dunaliella 16S rdna chloroplast sequences recovered from the photic zone of Fara Fund Lake: >DUNALIELLA_16S_1 TACAAGGGGAGCAAGCGTTATCCGGAATGATTGGGCGTAAAGCGTCTGTAGGTGGTTCTTTAAGTCTACTGTCAA ATACGTTGGCTCAACCAACGGCAGGCAGTAGAGTACTAAAGAACTAGAGTGCGGTAGAGGTAGAGGGAATCCCT AGCGTAACAGTGAAATGTGTAGATTTTAGGGGGAACACCAGCGGCGAAGGCGCTCTACTGGGCCGATACTGACA CTGAGAGACGAAAGCTAGAGGAGCGAATAGG >DUNALIELLA_16S_2 TACGGGGGGAGCAAGCGTTATCCGGAATGATTGGGCGTAAAGCGTCTGTAGGTGGTCCTTTAAGTCTACTGTTAA ATACGTTGGCTCAACCAACGGCAGGCAGTAGAGTACTAAAGGACTAGAGTGCGGTAGAGGTAGAGGGAATCCCT AGCGTAACAGTGAAATGTGTAGATTTTAGGGAGAACACCAGCGGCGAAGGCGCTCTACTGGGCCGATACTGACA CTGAGAGACGAAAGCTAGAGTAGCGAAAAGG
Figure 2. Epifluorescence microscopy image of Dunaliella sp. morphotypes at 3 m depth in Fara Fund Lake. The scale bar length is 10 µm.
Figure 3. Vertical profiles of oxygen concentrations in Fara Fund Lake measured in August 2011 and October 2013 Oxygen concentration (mg/l) 12 10 8 6 4 2 0 Fara Fund Lake 0 m 0.5 m 1 m 1.5 m 2 m 2.5 m 3 m 4 m 5 m 6 m 11-Aug 13-Oct The oxygen measurement in August 2011 was effectuated by Zsolt Keresztes (unpublished results).
Figure 4. Seasonal variations of salinity along the water column of Ursu Lake (Sovata, Romania) during 2012. 350 2012 seasonal variations of salinity in Ursu Lake 300 Salinity (g/l) 250 200 150 100 February June September November 50 0 1 2 3 4 5 6 7 8 9 10 11
Figure 5. Seasonal variations of ph along the water column of Ursu Lake (Sovata, Romania) during 2012. 9.00 2012 seasonal variations of ph in Ursu Lake 8.50 8.00 ph 7.50 7.00 6.50 February June September November 6.00 1 2 3 4 5 6 7
Figure 6. Seasonal variations of dissolved oxygen along the water column of Ursu Lake (Sovata, Romania) during 2012. Dissolved oxygen mg/l 10 9 8 7 6 5 4 3 2 1 0 2012 seasonal variations of dissolved oxygen in Ursu Lake 0.1 0.5 2 3 3.5 4 7 9 February June September November
Figure 7. Seasonal variations of temperature along the water column of Ursu Lake (Sovata, Romania) during 2012. Temperature C 40 35 30 25 20 15 10 5 0 2012 seasonal variations of temperature in Ursu Lake 0.1 0.5 2 3 3.5 4 7 9 February June September November
Figure 8. Seasonal variations of salinity along the water column of Fara Fund Lake (Sibiu, Romania) during 2012. 350 2012 seasonal variations of salinity in Fara Fund Lake 300 Salinity (g/l) 250 200 150 100 February May August October 50 0 0.1 0.5 1 1.5 2 2.5 3 3.5 4 5 8 11
Figure 9. Seasonal variations of ph along the water column of Fara Fund Lake (Sibiu, Romania) during 2012. 9 2012 seasonal variations of ph in Fara Fund Lake 8.5 8 ph 7.5 7 6.5 6 February May August October 5.5 5 0.5 2 3 3.5 4 8 11
Figure 10. Seasonal variations of dissolved oxygen along the water column of Fara Fund Lake (Sibiu, Romania) during 2012. 8 2012 seasonal variations of dissolved oxygen in Fara Fund Lake Dissolved oxygen mg/l 7 6 5 4 3 2 1 February May August October 0 0.5 2 3 3.5 4 8 11
Figure 11. Seasonal variations of temperature along the water column of Fara Fund Lake (Sibiu, Romania) during 2012. 32 2012 seasonal variations of temperature in Fara Fund Lake 28 Temperature C 24 20 16 12 8 February May August October 4 0 0.5 2 3 3.5 4 8 11
Figure 12. The XRD pattern of 3 m deep sediments from Ursu Lake. Abbreviations: Qua-quartz; Mus-muscovite; Hal-halite; Ano-anorthite; Cli-clinochlore; Fer-ferro-actinolite.
Figure 13. The XRD pattern of 16 m deep sediments from Ursu Lake. Abbreviations: Qua-quartz; Mus-muscovite; Ano-anorthite; Hal-halite; Cal-calcite; Cli-clinochlore
Figure 14. The XRD pattern of 2 m deep sediments from Fara Fund Lake. Abbreviations: Qua-quartz; Hal-halite; Cli-clinochlore; Mus-muscovite; Alb-albite.
Figure 15. The XRD pattern of 4 m deep sediments from Fara Fund Lake. Abbreviations: Qua-quartz; Hal-halite; Mus-muscovite; Alb-albite; Ano-anorthite.
Figure 16. DAPI epifluorescence microscopy images of Ursu Lake microbiota displaying coccus (A; 0.5 m deep) and vibrio (B; 9 m deep) morphotypes.
Figure 17. DAPI epifluorescence microscopy images of Fara Fund Lake microbiota displaying coccus (A; 0.5 m deep) and spirilla (B; 11 m deep) morphotypes.