title: Life based on phosphite: a genome-guided analysis of Desulfotignum phosphitoxidans.
abstract: BACKGROUND
  The Delta-Proteobacterium Desulfotignum phosphitoxidans is a type strain of the genus Desulfotignum, which comprises to date only three species together with D. balticum and D. toluenicum. D. phosphitoxidans oxidizes phosphite to phosphate as its only source of electrons, with either sulfate or CO2 as electron acceptor to gain its metabolic energy, which is of exclusive interest. Sequencing of the genome of this bacterium was undertaken to elucidate the genomic basis of this so far unique type of energy metabolism.
  
  
  RESULTS
  The genome contains 4,998,761 base pairs and 4646 genes of which 3609 were assigned to a function, and 1037 are without function prediction. Metabolic reconstruction revealed that most biosynthetic pathways of Gram negative, autotrophic sulfate reducers were present. Autotrophic CO2 assimilation proceeds through the Wood-Ljungdahl pathway. Additionally, we have found and confirmed the ability of the strain to couple phosphite oxidation to dissimilatory nitrate reduction to ammonia, which in itself is a new type of energy metabolism. Surprisingly, only two pathways for uptake, assimilation and utilization of inorganic and organic phosphonates were found in the genome. The unique for D. phosphitoxidans Ptx-Ptd cluster is involved in inorganic phosphite oxidation and an atypical C-P lyase-coding cluster (Phn) is involved in utilization of organophosphonates.
  
  
  CONCLUSIONS
  We present the whole genome sequence of the first bacterium able to gain metabolic energy via phosphite oxidation. The data obtained provide initial information on the composition and architecture of the phosphite-utilizing and energy-transducing systems needed to live with phosphite as an unusual electron donor.
authors.forename: Anja
authors.initials: A
authors.lastname: Poehlein
authors.forename: Rolf
authors.initials: R
authors.lastname: Daniel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schink
authors.affiliation: Laboratory of Microbial Ecology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany. Diliana.Simeonova@uni-konstanz.de.
authors.forename: Diliana D
authors.initials: DD
authors.lastname: Simeonova
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D020564:Deltaproteobacteria / Q000235:genetics* / Q000378:metabolism; D004734:Energy Metabolism; D016680:Genome, Bacterial; D059014:High-Throughput Nucleotide Sequencing; D008190:Lyases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D009584:Nitrogen / Q000378:metabolism; D017905:Phosphites / Q000737:chemistry / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D017905:Phosphites; D002245:Carbon Dioxide; D013455:Sulfur; D006180:Proton-Translocating ATPases; D008190:Lyases; C051328:carbon-phosphorus lyase; D009584:Nitrogen