microorganisms Article Uncovering Unique Green Algae and Cyanobacteria Isolated from Biocrusts in Highly Saline Potash Tailing Pile Habitats, Using an Integrative Approach Veronika Sommer 1,2, Tatiana Mikhailyuk 3, Karin Glaser 1 and Ulf Karsten 1,* 1 Institute for Biological Sciences, Applied Ecology and Phycology, University of Rostock, 18059 Rostock, Germany;
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[email protected] (K.G.) 2 upi UmweltProjekt Ingenieursgesellschaft mbH, 39576 Stendal, Germany 3 National Academy of Sciences of Ukraine, M.G. Kholodny Institute of Botany, 01601 Kyiv, Ukraine;
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[email protected] Received: 4 September 2020; Accepted: 22 October 2020; Published: 27 October 2020 Abstract: Potash tailing piles caused by fertilizer production shape their surroundings because of the associated salt impact. A previous study in these environments addressed the functional community “biocrust” comprising various micro- and macro-organisms inhabiting the soil surface. In that previous study, biocrust microalgae and cyanobacteria were isolated and morphologically identified amongst an ecological discussion. However, morphological species identification maybe is difficult because of phenotypic plasticity, which might lead to misidentifications. The present study revisited the earlier species list using an integrative approach, including molecular methods. Seventy-six strains were sequenced using the markers small subunit (SSU) rRNA gene and internal transcribed spacer (ITS). Phylogenetic analyses confirmed some morphologically identified species. However, several other strains could only be identified at the genus level. This indicates a high proportion of possibly unknown taxa, underlined by the low congruence of the previous morphological identifications to our results. In general, the integrative approach resulted in more precise species identifications and should be considered as an extension of the previous morphological species list.