Here we describe two new species of Oculatella Zammit, Billi & Albertano from terrestrial habitats of Ukraine: O. ucrainica sp. nov. and O. kazantipica sp. nov. The strains were isolated from biological crusts collected at the Sea of Azov conqina beach, and both clay slopes and chalk outcrops in the Kharkiv Region. Five strains evaluated in this study phenotypically and phylogenetically differed both among each other and from other species of this genus. On the phylogenetic tree based on 16S rRNA gene sequence comparison, original strains joined already known species of Oculatella forming isolated lineages, one of which joined the group of drought-resistant terrestrial species (O. ucrainica), while another (O. kazantipica) grouped together with terrestrial O. neakameniensis Kováčik et Johansen and aquatic O. hafneriensis Kováčik et Johansen. The phylogeny based on the 16S rRNA gene concatenated with the 16S-23S ITS region, as well as secondary structures of the most informative helices of the 16S-23S ITS confirmed new species designation. Filaments of O. ucrainica are narrower (1.5–3.0 µm), and trichomes are wider (1.3–2.7 µm) comparing to O. kazantipica (its filaments are 1.3–7.5 µm wide, trichomes 1.1–1.7 µm wide). The new species also differ from one another in sheath morphogenesis, appearence of trichomes, and cell length. Oculatella ucrainica morphologically and phylogenetically is close to desert species O. coburnii Pietrasiak et Johansen, differing in the higher degree of sheath formation, wider trichomes, apical cells without irregular outgrowth, and by composition and secondary structure of 16S-23S ITS region. O. kazantipica is similar to O. hafneriensis and O. neakameniensis, from which it differs in more abundant sheath, false branching, granulations at cross walls, longer intercalary cells, and by composition and secondary structure of its 16S-23S ITS region.

Keywords: Synechococcales, Oculatella ucrainica, Oculatella kazantipica, new species, biological crusts, Ukraine, molecular sequencing, 16S rRNA, 16S-23S ITS, secondary structure

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1. Akaike H. A new look at the statistical model identification. IEEE Trans. Automat. Contr., 1974, 19(6): 716–723. https://doi.org/10.1109/TAC.1974.1100705
2. Bischoff H.W., Bold H.C. Phycological studies. IV. Some soil algae from Enchanted Rock and related algal species. Univ. Texas Publ., 1963, 6318: 1–95.
3. Byun Y., Han K. PseudoViewer3: generating planar drawings of large-scale RNA structures with pseudoknots. Bioinformatics, 2009, 25(11): 1435–1437. https://doi.org/10.1093/bioinformatics/btp252 https://www.ncbi.nlm.nih.gov/pubmed/19369500
4. Dulić T., Meriluoto J., Malešević T.P., Gajić V., Važić T., Tokodi N., Obreht I., Kostić B., Kosijer P., Khormali F., Svirčev Z. Cyanobacterial diversity and toxicity of biocrusts from the Caspian Lowland loess deposits, North Iran. Quat. Int., 2017, 429: 74–85. https://doi.org/10.1016/j.quaint.2016.02.046
5. Holzinger A., Roleda M.Y., Lütz C. The vegetative arctic green alga Zygnema is insensitive to experimental UV exposure. Micron, 2009, 40: 831–838. https://doi.org/10.1016/j.micron.2009.06.008 https://www.ncbi.nlm.nih.gov/pubmed/19660959
6. Katoh K., Standley D.M. MAFT Multiple Sequence Alignment Software Version 7: improvements in performance and usability. Mol. Biol. and Evol., 2013, 30(4): 772–780. https://doi.org/10.1093/molbev/mst010 https://www.ncbi.nlm.nih.gov/pubmed/23329690 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603318
7. Marin B., Nowack E.C.M., Melkonian M. A plastid in the making: evidence for a second primary endosymbiosis. Protist, 2005, 156: 425–432. https://doi.org/10.1016/j.protis.2005.09.001 https://www.ncbi.nlm.nih.gov/pubmed/16310747
8. Mikhailyuk T.I., Vinogradova O.N., Glaser K., Karsten U. New taxa for the flora of Ukraine, in the context of modern approaches to taxonomy of Cyanoprokaryota/Cyanobacteria. Int. J. on Algae, 2016, 18(4): 301–320. https://doi.org/10.1615/InterJAlgae.v18.i4.10
9. Osorio-Santos K., Pietrasiak N., Bohunická M., Miscoe L.H., Kováčik L., Martin M.P., Johansen J.R. Seven new species of Oculatella (Pseudanabaenales, Cyanobacteria): taxonomically recognizing cryptic diversification. Eur. J. Phycol., 2014, 49(4): 450–470. https://doi.org/10.1080/09670262.2014.976843
10. Ronquist F., Huelsenbeck J.R. MrBayes 3: Bayesian phylogenetic interference under mixed models. Bioinformatics, 2003, 19(12): 1572–1574. https://doi.org/10.1093/bioinformatics/btg180
11. Stanier R.Y., Kunisawa R., Mandel M., Cohen-Bazire G. Purification and properties of unicellular blue-green algae (order Chroococcales). Bacteriol. Rev., 1971, 35: 171–205. https://www.ncbi.nlm.nih.gov/pubmed/4998365 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC378380
12. Tamura K., Stecher G., Peterson D., Filipski A. MEGA6: molecular evolutionary analysis version 6.0. Mol. Biol. and Evol., 2013, 30(12): 2725–2729. https://doi.org/10.1093/molbev/mst197 https://www.ncbi.nlm.nih.gov/pubmed/24132122 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3840312
13. Wilmotte A., Van der Auwera G., De Wachter R. Structure of the 16S ribosomal RNA of the thermophilic cyanobacterium Chlorogloeopsis HTF (Mastigocladus laminosus HTF') strain PCC75 18, and phylogenetic analysis. FEBS Lett., 1993, 317(1–2): 96–100. https://doi.org/10.1016/0014-5793(93)81499-P
14. Zammit G., Billi D., Albertano P. The subaerophytic cyanobacterium Oculatella subterranea (Oscillatoriales, Cyanophyceae) gen. et sp. nov.: a cytomorphological and molecular description. Eur. J. Phycol., 2012, 47: 341–354. https://doi.org/10.1080/09670262.2012.717106
15. Zuker M. Mfold web server for nucleic acid folding and hybridization prediction. Nucl. Acid Res., 2003, 31(13): 3406–3415. https://doi.org/10.1093/nar/gkg595 https://www.ncbi.nlm.nih.gov/pubmed/12824337 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC169194