G C A T T A C G G C A T genes Article Diversity and Horizontal Transfer of Antarctic Pseudomonas spp. Plasmids Krzysztof Romaniuk 1, Michal Styczynski 1, Przemyslaw Decewicz 1 , Oliwia Buraczewska 1, Witold Uhrynowski 1 , Marco Fondi 2 , Marcin Wolosiewicz 1, Magdalena Szuplewska 1 and Lukasz Dziewit 1,* 1 Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland;
[email protected] (K.R.);
[email protected] (M.St.);
[email protected] (P.D.);
[email protected] (O.B.);
[email protected] (W.U.);
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[email protected] (M.Sz.) 2 Department of Biology, University of Florence, via Madonna del Piano 6, Sesto Fiorentino, 50019 Florence, Italy; marco.fondi@unifi.it * Correspondence:
[email protected]; Tel.: +48-225-541-406 Received: 12 September 2019; Accepted: 26 October 2019; Published: 28 October 2019 Abstract: Pseudomonas spp. are widely distributed in various environments around the world. They are also common in the Antarctic regions. To date, almost 200 plasmids of Pseudomonas spp. have been sequenced, but only 12 of them were isolated from psychrotolerant strains. In this study, 15 novel plasmids of cold-active Pseudomonas spp. originating from the King George Island (Antarctica) were characterized using a combined, structural and functional approach, including thorough genomic analyses, functional analyses of selected genetic modules, and identification of active transposable elements localized within the plasmids and comparative genomics. The analyses performed in this study increased the understanding of the horizontal transfer of plasmids found within Pseudomonas populations inhabiting Antarctic soils.