A rapid and reliable method for NO quantification and 15NO/14NO determination using isotope ratio mass spectrometry: an application for the detection of NO synthesis in propionibacteria.
For the last decade, numerous studies have focused on the positive or toxic effects of nitric oxide (NO) in procaryotic and eucaryotic cells. This gas has fundamental roles in neurotransmission, vasodilatation, cytotoxicity, and intestinal motility. The ability to produce NO by intestinal microflora or probiotic bacteria is unknown. In this preliminary study, we present a rapid and reproducible procedure for NO quantification and 15NO/14NO determination (based on the reaction between nitrite and acidic potassium iodide) by isotope ratio mass spectrometry. Using this method, we have demonstrated for the first time in vitro production of NO by a dietary bacterium (Propionibacterium acidipropionici, Pa 1) under anaerobic culture conditions. Using different sources of nitrogen, we have clearly shown that propionibacteria can synthesize NO from reduction of nitrate or nitrite. In our experimental conditions, NO synthase was not involved in NO production by propionibacteria.
Avice
J C
JC
U.A. INRA 950 Physiologie et Biochimie végétales, Université de Caen, France. Ledeunff@ibba.unicaen.fr
Ourry
A
A
Lainé
P
P
Roland
N
N
Louahlia
S
S
Roussel
E
E
Brookes
S
S
Boucaud
J
J
D000693:Anaerobiosis; D013058:Mass Spectrometry / Q000379:methods*; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000032:analysis* / Q000096:biosynthesis; D009573:Nitrites / Q000378:metabolism; D009587:Nitrogen Isotopes; D011193:Potassium Iodide; D011424:Propionibacterium / Q000378:metabolism*
D009566:Nitrates; D009573:Nitrites; D009587:Nitrogen Isotopes; D011193:Potassium Iodide; D009569:Nitric Oxide