GERBAM — Deuxième Colloque International de Bactériologie marine — CNRS, Brest, 1-5 octobre 1984
IFREMER, Actes de Colloques, 3, 1986, pp. 311-317
36
METABOLISM OF CO AND CH 4 BY NITRIFIERS AND THE DETERMINATION
OF THE NITRIFICATION RATE
R.Y. MORITA and R.D. JONES
Department of Microbiology and the College of Oceanography, Oregon, State University, CORVALLIS, Oregon, 97331-3804 (USA)
ABSTRACT - The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without
decreasing their number or cell size. Because H 2 , CO, and CH 4 are present in the marine environment, these
substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. 14 CO
and
14 CH 4 were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using
the nitrifiers’ ability to oxide CO, a method for the determination of the nitrification rate was developed. The
ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO2 in the marine environment.
Whether CO and CH 4 oxidation play a role in the survival of nitrifiers in the absence of ammonium is currently
being tested.
Key words: survival, CO oxidation, CEL oxidation, nitrifiers, CO2 cycling.
RÉSUMÉ - Les bactéries nitrifiantes peuvent survivre 24 semaines en absence d’ammonium sans diminution de
leur nombre ou de la taille des cellules. H 2 , CO et CEL étant présents dans l’environnement marin, ces substrats
sont envisagés comme une source éventuelle d’énergie de maintenance pour les bactéries nitrifiantes. On a
montré que
14 CO et 14 CH 4 sont oxydés par les nitrifiants et que N-Serve inhibe l’oxydation de CO. En utilisant
la capacité des nitrifiants à oxyder CO, une méthode pour déterminer le taux de nitrification est développée.
Dans l’environnement marin, la capacité des nitrifiants à oxyder CO peut jouer un rôle important dans le cycle
du CO2. D’autre part, le rôle que joue l’oxydation de CO et CEL dans la survie des nitrifiants en absence
d’ammonium a été fréquemment testé.
Mots-clés : survie, oxydation de CO, oxydation de CEL, nitrifiants, cycle de CO 2 .
During our studies on starvation survival, the chemolithotrophic ammonium oxidizing
bacteria were selected to determine if they could survive long periods of time in the
absence of ammonium as the energy source. Since ammonia cannot be detected chemically in some water masses, the ability of the nitrifiers to survive this condition was viewed
to be important, especially when one considers the cycling of nitrogen in the aquatic
environment. Thus far, we have been able to demonstrate that, without the addition of
ammonium to the starvation menstruum, the nitrifiers remained viable until the termination of the experiment (24 weeks). During this period, the nitrifiers did not decrease in
numbers or size. Therefore, the question of the possibility of an alternative energy
source(s) for cellular maintenance was addressed.
In assessing the possible energy sources available in the oligotrophic waters of the oceans,
it became clear that the gases (CH 4 , CO, and H2) should not be overlooked as potential
sources of maintenance energy, but not necessarily as a source of energy for growth and
reproduction. Some of these gases are supersaturated in the ocean. The distribution and
311
IFREMER, Actes de Colloques, 3, 1986, pp. 311-317
36
METABOLISM OF CO AND CH 4 BY NITRIFIERS AND THE DETERMINATION
OF THE NITRIFICATION RATE
R.Y. MORITA and R.D. JONES
Department of Microbiology and the College of Oceanography, Oregon, State University, CORVALLIS, Oregon, 97331-3804 (USA)
ABSTRACT - The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without
decreasing their number or cell size. Because H 2 , CO, and CH 4 are present in the marine environment, these
substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. 14 CO
and
14 CH 4 were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using
the nitrifiers’ ability to oxide CO, a method for the determination of the nitrification rate was developed. The
ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO2 in the marine environment.
Whether CO and CH 4 oxidation play a role in the survival of nitrifiers in the absence of ammonium is currently
being tested.
Key words: survival, CO oxidation, CEL oxidation, nitrifiers, CO2 cycling.
RÉSUMÉ - Les bactéries nitrifiantes peuvent survivre 24 semaines en absence d’ammonium sans diminution de
leur nombre ou de la taille des cellules. H 2 , CO et CEL étant présents dans l’environnement marin, ces substrats
sont envisagés comme une source éventuelle d’énergie de maintenance pour les bactéries nitrifiantes. On a
montré que
14 CO et 14 CH 4 sont oxydés par les nitrifiants et que N-Serve inhibe l’oxydation de CO. En utilisant
la capacité des nitrifiants à oxyder CO, une méthode pour déterminer le taux de nitrification est développée.
Dans l’environnement marin, la capacité des nitrifiants à oxyder CO peut jouer un rôle important dans le cycle
du CO2. D’autre part, le rôle que joue l’oxydation de CO et CEL dans la survie des nitrifiants en absence
d’ammonium a été fréquemment testé.
Mots-clés : survie, oxydation de CO, oxydation de CEL, nitrifiants, cycle de CO 2 .
During our studies on starvation survival, the chemolithotrophic ammonium oxidizing
bacteria were selected to determine if they could survive long periods of time in the
absence of ammonium as the energy source. Since ammonia cannot be detected chemically in some water masses, the ability of the nitrifiers to survive this condition was viewed
to be important, especially when one considers the cycling of nitrogen in the aquatic
environment. Thus far, we have been able to demonstrate that, without the addition of
ammonium to the starvation menstruum, the nitrifiers remained viable until the termination of the experiment (24 weeks). During this period, the nitrifiers did not decrease in
numbers or size. Therefore, the question of the possibility of an alternative energy
source(s) for cellular maintenance was addressed.
In assessing the possible energy sources available in the oligotrophic waters of the oceans,
it became clear that the gases (CH 4 , CO, and H2) should not be overlooked as potential
sources of maintenance energy, but not necessarily as a source of energy for growth and
reproduction. Some of these gases are supersaturated in the ocean. The distribution and
311