R E S E A R C H A R T I C L E Free-living and aggregate-associated Planctomycetes in the Black Sea Clara A. Fuchsman1, James T. Staley2, Brian B. Oakley2, John B. Kirkpatrick1 & James W. Murray1 1School of Oceanography, University of Washington, Seattle, WA, USA; and 2Department of Microbiology, University of Washington, Seattle, WA, USA Correspondence: Clara A. Fuchsman, Abstract School of Oceanography, University of Washington, Seattle WA 98195-5351, USA. We examined the distribution of uncultured Planctomycetes phylotypes along Tel.: +206 543 9669; fax: +206 685 3351; depth profiles spanning the redox gradient of the Black Sea suboxic zone to e-mail:
[email protected] gain insight into their respective ecological niches. Planctomycetes phylogeny correlated with depth and chemical profiles, implying similar metabolisms Present addresses: Brian B. Oakley, USDA within phylogenetic groups. A suboxic zone sample was split into > 30 and Agricultural Research Service, Athens, GA, < 30 lm fractions to examine putative aggregate-attached and free-living 30606, USA; Planctomycetes. All identified Planctomycetes were present in the > 30 m John B. Kirkpatrick, Graduate School of l Oceanography, University of Rhode Island, fraction except for members of the Scalindua genus, which were apparently Narragansett, RI, USA. free-living. Sequences from Candidatus Scalindua, known to carry out the anammox process, formed two distinct clusters with nonoverlapping depth Received 20 July 2011; revised 4 January ranges. One cluster, only 97.1% similar to the named species, was present at 2012; accepted 5 January 2012. high nitrite/nitrate and low ammonium concentrations in the upper suboxic zone. We propose this sequence type be named ‘Candidatus Scalindua richard- DOI: 10.1111/j.1574-6941.2012.01306.x sii’.