Authors: Ralf Rabus Michael Kube Johann Heider Alfred Beck Katja Heitmann Friedrich Widdel Richard Reinhardt
Publish Date: 2004/11/13
Volume: 183, Issue: 1, Pages: 27-36
Abstract
Recent research on microbial degradation of aromatic and other refractory compounds in anoxic waters and soils has revealed that nitratereducing bacteria belonging to the Betaproteobacteria contribute substantially to this process Here we present the first complete genome of a metabolically versatile representative strain EbN1 which metabolizes various aromatic compounds including hydrocarbons A circular chromosome 43 Mb and two plasmids 021 and 022 Mb encode 4603 predicted proteins Ten anaerobic and four aerobic aromatic degradation pathways were recognized with the encoding genes mostly forming clusters The presence of paralogous gene clusters eg for anaerobic phenylacetate oxidation high sequence similarities to orthologs from other strains eg for anaerobic phenol metabolism and frequent mobile genetic elements eg more than 200 genes for transposases suggest high genome plasticity and extensive lateral gene transfer during metabolic evolution of strain EbN1 Metabolic versatility is also reflected by the presence of multiple respiratory complexes A large number of regulators including more than 30 twocomponent and several FNRtype regulators indicate a finely tuned regulatory network able to respond to the fluctuating availability of organic substrates and electron acceptors in the environment The absence of genes required for nitrogen fixation and specific interaction with plants separates strain EbN1 ecophysiologically from the closely related nitrogenfixing plant symbionts of the Azoarcus cluster Supplementary material on sequence and annotation are provided at the Web page http//wwwmicrogenomesmpgde/ebn1/We acknowledge Katja Borzym Ines Müller Janina Thiel Susan Böhm Sven Klages Beatrice Baumann Daniela Gröger Verena Gimmel Mario Sontag Maximilian Weiss Berlin and Daniela Lange Bremen for technical assistance and Dirk Jacobs Berlin for computational support with the HTGA system This study was supported by the Max Planck Society
Keywords: