Comamonas testosteroni CNB-2

Names Comamonas testosteroni CNB-2
Accession numbers NC_013446
Background Comamonas testosteroni (strain CNB-2), named based on its ability to metabolize testosterone, is an obligately aerobic, Gram-negative bacterium derived from strain CNB-1 which was isolated from CNB-contaminated activated sludge and grows with 4-chloronitrobenzene (CNB) as a sole source of carbon and nitrogen. It has a circular chromosome and a large plasmid with the genes involved in the degradation of CNB. Strain CNB-1 has been used successfully for rhizoremediation of CNB-polluted soil. C. testosteroni (strain CNB-2) is a mutant of C. testosteroni (strain CNB-1) that lost the degrading plasmid pCNB1. The genome of CNB-2 contains large numbers of mobile genetic elements (MGEs) and 3 putative prophages (prophages I, II, and III) which harbor accessory genes possibly acquired by horizontal gene transfer (HGT) from other bacterial species. In the region from 2.75 to 2.97 Mbp contains gene clusters, acquired via HTG, putatively involved in xenobiotic compound degradation (e.g., protocatechuate degradation pathway) and heavy metal resistance (copper and arsenate resistance). Strain CNB-2 is able to synthesize all its cellular components, such as fatty acids, purine and pyrimidine nucleotides, and the 20 amino acids. However, it is not able to assimilate any sugar except glycerol and gluconate. The glycolysis in glucose catabolism is incomplete due to the lack of hexokinase and glucokinase genes. Genes encoding glucose-6-phosphate 1-ehydrogenase and 6-phosphogluconolactonase of the pentose phosphate pathway are not present. Thus, oxidation of glucose via this pentose phosphate pathway is not possible. However, the nonoxidative part of the pentose phosphate pathway is complete, and five-carbon sugars are generated for biosynthesis. Strain CNB-2 is able to utilize many other kinds of compounds, such as aromatics and short-chain fatty acids, as carbon sources. In the CNB-2 genome, 37, 18, and 47 genes encoding putative dioxygenases, hydroxylases, and oxidoreductases, respectively, are annotated for aromatic and cyclic hydrocarbon degradation. Strain CNB-2 is able to grow on benzoate, gentisate, phenol, 3-hydroxybenzoate, 4-hydroxybenzoate, protocatechuate, and vanillate. It uses nitrate and ammonium as nitrogen sources, and inorganic nitrogen is incorporated into glutamine by glutamine synthetase. Exogenous amino acids, oligopeptides, and branched-chain amino acids could be metabolized through the urea cycle and tricarboxylic acid cycle, which could supply not only an adequate nitrogen source but also a carbon source for cell growth. Several loci of the CNB-2 genome are predicted to be responsible for drug and heavy metal export. Strain CNB-2 has many chaperones that help the cell overcome toxicity. (Adapted from PMID: 19734336). (EBI Integr8)
Strain CNB1
Complete Yes
Sequencing centre (04-NOV-2009) National Center for Biotechnology Information, NIH, Bethesda, MD 20894, USA
(30-OCT-2008) Environmental Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Datun Road,
Sequencing quality Level 6: Finished
Sequencing depth NA
Sequencing method Sanger
Isolation site activated sludge from a chemical plant
Isolation country NA
Number of replicons 1
Gram staining properties Negative
Shape Bacilli
Mobility No
Flagellar presence Yes
Number of membranes 2
Oxygen requirements Aerobic
Optimal temperature NA
Temperature range Mesophilic
Habitat Multiple
Biotic relationship Free living
Host name NA
Cell arrangement NA
Sporulation Nonsporulating
Metabolism Surfactant-degrading
Energy source NA
Diseases NA
Pathogenicity No