Denitrification in human dental plaque

Schreiber, F., Stief, P., Gieseke, A., Heisterkampa, I., Verstraete, W., DeBeer, D. and Stoodley, P. (2010) Denitrification in human dental plaque BMC Biology, 8, (24) (doi:10.1186/1741-7007-8-24).


Full text not available from this repository.


Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate (NO3-) concentrations in the millimolar range and that dental plaque houses bacteria that can reduce this NO3- to nitrite (NO2-).

We show that dental plaque mediates denitrification of NO3- to nitric oxide (NO), nitrous oxide (N2O), and dinitrogen (N2) using microsensor measurements, 15N isotopic labelling and molecular detection of denitrification genes. In vivo N2O accumulation rates in the mouth depended on the presence of dental plaque and on salivary NO3- concentrations. NO and N2O production by denitrification occurred under aerobic conditions and was regulated by plaque pH.

Increases of NO concentrations were in the range of effective concentrations for NO signalling to human host cells and, thus, may locally affect blood flow, signalling between nerves and inflammatory processes in the gum. This is specifically significant for the understanding of periodontal diseases, where NO has been shown to play a key role, but where gingival cells are believed to be the only source of NO. More generally, this study establishes denitrification by human-associated microbial communities as a significant metabolic pathway which, due to concurrent NO formation, provides a basis for symbiotic interactions.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1186/1741-7007-8-24
Additional Information: The National Centre for Advanced Tribology at Southampton (nCATS)
ISSNs: 1471-2180 (print)
Related URLs:
Keywords: Denitrification as a source for nitric oxide and nitrous oxide in human dental plaque
Organisations: Engineering Mats & Surface Engineerg Gp
ePrint ID: 71665
Date :
Date Event
April 2010Published
Date Deposited: 17 Dec 2009
Last Modified: 18 Apr 2017 21:02
Further Information:Google Scholar

Actions (login required)

View Item View Item