The sulfonated osmolyte N-methyltaurine is dissimilated by Alcaligenes faecalis and by Paracoccus versutus with release of methylamine.
Selective enrichments yielded bacterial cultures able to utilize the osmolyte N-methyltaurine as sole source of carbon and energy or as sole source of fixed nitrogen for aerobic growth. Strain MT1, which degraded N-methyltaurine as a sole source of carbon concomitantly with growth, was identified as a strain of Alcaligenes faecalis. Stoichiometric amounts of methylamine, whose identity was confirmed by matrix-assisted, laser-desorption ionization time-of-flight mass spectrometry, and of sulfate were released during growth. Inducible N-methyltaurine dehydrogenase, sulfoacetaldehyde acetyltransferase (Xsc) and a sulfite dehydrogenase could be detected. Taurine dehydrogenase was also present and it was hypothesized that taurine dehydrogenase has a substrate range that includes N-methyltaurine. Partial sequences of a tauY-like gene (encoding the putative large component of taurine dehydrogenase) and an xsc gene were obtained by PCR with degenerate primers. Strain N-MT utilized N-methyltaurine as a sole source of fixed nitrogen for growth and could also utilize the compound as sole source of carbon. This bacterium was identified as a strain of Paracoccus versutus. This organism also expressed inducible (N-methyl)taurine dehydrogenase, Xsc and a sulfite dehydrogenase. The presence of a gene cluster with high identity to a larger cluster from Paracoccus pantotrophus NKNCYSA, which is now known to dissimilate N-methyltaurine via Xsc, allowed most of the overall pathway, including transport and excretion, to be defined. N-Methyltaurine is thus another compound whose catabolism is channelled directly through sulfoacetaldehyde.
Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.
Sonja
S
Weinitschke
Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.
Karin
K
Denger
Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.
Theo H M
THM
Smits
Institute of Biochemical Engineering, Saarland University, Box 50 11 50, D-66041 Saarbrücken, Germany.
Klaus
K
Hollemeyer
Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.
Alasdair M
AM
Cook
D000123:Acetyltransferases / Q000032:analysis; D042481:Alcaligenes faecalis / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics; D002244:Carbon / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D013058:Mass Spectrometry; D008744:Methylamines / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009584:Nitrogen / Q000378:metabolism; D010088:Oxidoreductases / Q000032:analysis; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000032:analysis; D010230:Paracoccus / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology; D050902:Sulfite Dehydrogenase / Q000032:analysis; D013654:Taurine / Q000031:analogs & derivatives* / Q000378:metabolism*; D014871:Water Microbiology
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008744:Methylamines; D012722:Sewage; D013654:Taurine; D002244:Carbon; C027451:methylamine; D010088:Oxidoreductases; C053682:taurine dehydrogenase; D000587:Oxidoreductases Acting on CH-NH Group Donors; D050902:Sulfite Dehydrogenase; D000123:Acetyltransferases; D009584:Nitrogen