1. ¹Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Bremen, Germany
2. ²Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
3. ³School of Engineering and Sciences, Jacobs University Bremen gGmbH, Bremen, Germany
4. ⁴Division of Biological Engineering & Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA

Correspondence: H Teeling, Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, Bremen 28359, Germany. E-mail: hteeling@mpi-bremen.de

Received 7 May 2007; Revised 26 June 2007; Accepted 27 June 2007; Published online 9 August 2007.

Abstract

Planctomycetes are widely distributed in marine environments, where they supposedly play a role in carbon recycling. To deepen our understanding about the ecology of this sparsely studied phylum six planctomycete fosmids from two marine upwelling systems were investigated and compared with all available planctomycete genomic sequences including the as yet unpublished near-complete genomes of Blastopirellula marina DSM 3645^T and Planctomyces maris DSM 8797^T. High numbers of sulfatase genes (41–109) were found on all marine planctomycete genomes and on two fosmids (2). Furthermore, C1 metabolism genes otherwise only known from methanogenic Archaea and methylotrophic Proteobacteria were found on two fosmids and all planctomycete genomes, except for 'Candidatus Kuenenia stuttgartiensis'. Codon usage analysis indicated high expression levels for some of these genes. In addition, novel large families of planctomycete-specific paralogs with as yet unknown functions were identified, which are notably absent from the genome of 'Candidatus Kuenenia stuttgartiensis'. The high numbers of sulfatases in marine planctomycetes characterizes them as specialists for the initial breakdown of sulfatated heteropolysaccharides and indicate their importance for recycling carbon from these compounds. The almost ubiquitous presence of C1 metabolism genes among Planctomycetes together with codon usage analysis and information from the genomes suggest a general importance of these genes for Planctomycetes other than formaldehyde detoxification. The notable absence of these genes in Candidatus K. stuttgartiensis plus the surprising lack of almost any planctomycete-specific gene within this organism reveals an unexpected distinctiveness of anammox bacteria from all other Planctomycetes.