title: Highly enriched Betaproteobacteria growing anaerobically with p-xylene and nitrate.
abstract: The identity of the microorganisms capable of anaerobic p-xylene degradation under denitrifying conditions is hitherto unknown. Here, we report highly enriched cultures of freshwater denitrifying bacteria that grow anaerobically with p-xylene as the sole organic carbon source and electron donor. Long curved rods, with 95% 16S rRNA gene sequence identity to Denitratisoma oestradiolicum, dominated the enrichment cultures (>91% of all cells), as detected by phylotype-specific probes. These Rhodocyclaceae microorganisms were distantly related to other denitrifying hydrocarbon-degrading Betaproteobacteria from the Azoarcus-Thauera clade. Complete oxidation p-xylene to CO(2) coupled to denitrification was suggested by quantitative measurements of substrate consumption. Metabolite analysis identified (4-methylbenzyl)succinate and (4-methylphenyl)itaconate, suggesting addition to fumarate as an initial activation reaction.
authors: Department of Microbiology, Max Planck Institute for Marine Microbiology, Bremen, Germany.
authors: Amelia-Elena
authors: AE
authors: Rotaru
authors: Christina
authors: C
authors: Probian
authors: Heinz
authors: H
authors: Wilkes
authors: Jens
authors: J
authors: Harder
mesh_terms: D000693:Anaerobiosis; D020627:Azoarcus / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020562:Betaproteobacteria / Q000145:classification / Q000254:growth & development* / Q000378:metabolism; D005618:Fresh Water; D008401:Gas Chromatography-Mass Spectrometry; D020459:Genes, rRNA; D009566:Nitrates / Q000378:metabolism*; D010802:Phylogeny; D020628:Thauera / Q000235:genetics / Q000378:metabolism; D014992:Xylenes / Q000378:metabolism*
chemical_list: D009566:Nitrates; D014992:Xylenes; C031286:4-xylene