Dynamics of denitrification activity of Paracoccus denitrificans in continuous culture during aerobic-anaerobic changes.

Détails

ID Serval
serval:BIB_8DD81AB15F86
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Dynamics of denitrification activity of Paracoccus denitrificans in continuous culture during aerobic-anaerobic changes.
Périodique
Journal of Bacteriology
Auteur(s)
Baumann B., Snozzi M., Zehnder A.J., Van Der Meer J.R.
ISSN
0021-9193 (Print)
ISSN-L
0021-9193
Statut éditorial
Publié
Date de publication
1996
Peer-reviewed
Oui
Volume
178
Numéro
15
Pages
4367-4374
Langue
anglais
Résumé
Induction and repression of denitrification activity were studied in a continuous culture of Paracoccus denitrificans during changes from aerobic to anaerobic growth conditions and vice versa. The denitrification activity of the cells was monitored by measuring the formation of denitrification products (nitrite, nitric oxide, nitrous oxide, and dinitrogen), individual mRNA levels for the nitrate, nitrite, and nitrous oxide reductases, and the concentration of the nitrite reductase enzyme with polyclonal antibodies against the cd1-type nitrite reductase. On a change from aerobic to anaerobic respiration, the culture entered an unstable transition phase during which the denitrification pathway became induced. The onset of this phase was formed by a 15- to 45-fold increase of the mRNA levels for the individual denitrification enzymes. All mRNAs accumulated during a short period, after which their overall concentration declined to reach a stable value slightly higher than that observed under aerobic steady-state conditions. Interestingly, the first mRNAs to be formed were those for nitrate and nitrous oxide reductase. The nitrite reductase mRNA appeared significantly later, suggesting different modes of regulation for the three genes. Unlike the mRNA levels, the level of the nitrite reductase protein increased slowly during the anaerobic period, reaching a stable value about 30 h after the switch. All denitrification intermediates could be observed transiently, but when the new anaerobic steady state was reached, dinitrogen was the main product. When the anaerobic cultures were switched back to aerobic respiration, denitrification of the cells stopped at once, although sufficient nitrite reductase was still present. We could observe that the mRNA levels for the individual denitrification enzymes decreased slightly to their aerobic, uninduced levels. The nitrite reductase protein was not actively degraded during the aerobic period.
Mots-clé
Aerobiosis, Amino Acid Sequence, Anaerobiosis, Base Sequence, Cloning, Molecular, DNA Primers/genetics, DNA, Bacterial/genetics, Genes, Bacterial, Molecular Sequence Data, Nitrate Reductase, Nitrate Reductases/genetics, Nitric Oxide/metabolism, Nitrite Reductases/genetics, Nitrites/metabolism, Nitrogen/metabolism, Nitrous Oxide/metabolism, Oxidation-Reduction, Oxidoreductases/genetics, Paracoccus denitrificans/genetics, Paracoccus denitrificans/growth & development, RNA, Messenger/genetics, RNA, Messenger/metabolism
Pubmed
Web of science
Création de la notice
21/01/2008 14:35
Dernière modification de la notice
03/03/2018 19:17
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