FEMS Microbiology Ecology, 91, 2015 doi: 10.1093/femsec/iu012 Advance Access Publication Date: 5 December 2014 Short communication SHORT COMMUNICATION Characterization of a lytic cyanophage that infects the bloom-forming cyanobacterium Aphanizomenon los-aquae Sigitas ˇ Sulˇ cius 1, ∗ , Eugenijus ˇ Simoli ¯ unas 2 , Juozas Staniulis 3 , Judita Koreivien˙ e 4 , Paulius Baltruˇ sis 5 , Rolandas Meˇ skys 2 and Ri ˇ cardas Paˇ skauskas 1, 4 1 Marine Science and Technology Centre, Klaipeda University, Herkaus Manto str. 84, LT-92294 Klaipeda, Lithuania, 2 Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Mokslininku str. 12, LT-08662 Vilnius, Lithuania, 3 Laboratory of Plant Viruses, Institute of Botany, Nature Research Centre, Mokslininku str. 12, LT-08662 Vilnius, Lithuania, 4 Laboratory of Algology and Microbial Ecology, Institute of Botany, Nature Research Centre, Akademijos str. 2, LT-08412 Vilnius, Lithuania and 5 Department of Biochemistry and Molecular Biology, Faculty of Natural Sciences, Vilnius University, M. K. Ciurlionio str. 21/27, LT-03101 Vilnius, Lithuania ∗ Corresponding author: Marine Science and Technology Centre, Klaipeda University, Herkaus Manto str. 84, LT-92294 Klaipeda, Lithuania. Tel: +370-645-91880; E-mail: sigitas.sulcius@gmail.com One sentence summary: Novel cyanosiphovirus that infects Aphanizomenon los-aquae, a ilamentous nitrogen-ixing cyanobacterium that regularly produces harmful blooms in fresh and brackish water environments. Editor: Riks Laanbroe ABSTRACT Vb-AphaS-CL131 is a novel cyanosiphovirus that infects harmful Aphanizomenon los-aquae. This cyanophage has an isometric head, 97 nm in diameter and a long, lexible non-contractile tail, 361 nm long. With a genome size of ∼120 kb, it is the second largest cyanosiphovirus isolated to date. The latent period was estimated to be ∼36 h and a single infected cell produces, on average, 218 infectious cyanophages. Cyanophage infection signiicantly suppresses host biomass production and alters population phenotype. Key words: Baltic Sea; Curonian Lagoon; Siphoviridae Aphanizomenon los-aquae Ralfs ex Bornet et Flahault is a ila- mentous diazotrophic cyanobacterium that regularly produces harmful blooms in temperate fresh and brackish water envi- ronments (Paerl and Otten 2013). Intensive growth of these cyanobacteria greatly alters food web structure, carbon lux and nutrient cycles (Ploug 2008; Ploug et al., 2010). Some A. los-aquae strains were found to produce toxins and teratogens that ad- versely affect higher trophic levels (Preußel et al., 2006; Wu et al., 2012). The control of A. los-aquae by grazing is often negligi- ble (Sellner, Olson and Kononen 1994; Hambright et al., 2001) as feeding by zooplankton can be inhibited both by toxin produc- tion and mechanically by ilaments of A. los-aquae (Rollwagen- Bollens et al., 2013). Moreover, preferential exclusion of A. los- aquae from the diet of zooplankton indirectly promotes bloom Received: 26 May 2014; Accepted: 5 November 2014 C  FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com 1 by guest on February 7, 2016 http://femsec.oxfordjournals.org/ Downloaded from