TY - JOUR
T1 - Dissimilatory nitrate uptake in Paracoccus denitrificans via a ΔµH+-dependent system and a nitrate-nitrite antiport system
AU - Boogerd, F. C.
AU - Van Verseveld, H. W.
AU - Stouthamer, A.H.
PY - 1983/6/30
Y1 - 1983/6/30
N2 - Respiration-driven proton translocation has been studied with the oxidant pulse method for cells of denitrifying Paracoccus denitrificans oxidizing H2 during reduction of O2, NO-
3, NO-
2 or N2O. A simplified scheme of anaerobic electron transport and associated proton translocation is shown that is consistent with the measured H+ oxidant ratios. Furthermore, the kinetics and energetics of NO-
3 uptake in whole cells of P. denitrificans were studied. For this purpose, we measured H2 consumption or N2O production after addition of NO-
3 to a cell suspension, which indirectly gave information about uptake (and reduction) of NO-
3. It was found that a lag phase in H2 consumption or N2O production appeared whenever the membrane potential was dissipated by addition of thiocyanate, carbonyl cyanide m-chlorophenylhydrazone or triphenyl-methylphosphonium bromide. However, these lag phases were not observed when NO-
2 was present at the moment of introduction of NO-
3. On the basis of these findings we conclude that there are two uptake systems for NO-
3. One system is dependent on the proton-motive force and is probably used for initiation of NO-
3 uptake. The other is an NO-
3 NO-
2 antiport and its function is to take over NO-
3 uptake from the first system.
AB - Respiration-driven proton translocation has been studied with the oxidant pulse method for cells of denitrifying Paracoccus denitrificans oxidizing H2 during reduction of O2, NO-
3, NO-
2 or N2O. A simplified scheme of anaerobic electron transport and associated proton translocation is shown that is consistent with the measured H+ oxidant ratios. Furthermore, the kinetics and energetics of NO-
3 uptake in whole cells of P. denitrificans were studied. For this purpose, we measured H2 consumption or N2O production after addition of NO-
3 to a cell suspension, which indirectly gave information about uptake (and reduction) of NO-
3. It was found that a lag phase in H2 consumption or N2O production appeared whenever the membrane potential was dissipated by addition of thiocyanate, carbonyl cyanide m-chlorophenylhydrazone or triphenyl-methylphosphonium bromide. However, these lag phases were not observed when NO-
2 was present at the moment of introduction of NO-
3. On the basis of these findings we conclude that there are two uptake systems for NO-
3. One system is dependent on the proton-motive force and is probably used for initiation of NO-
3 uptake. The other is an NO-
3 NO-
2 antiport and its function is to take over NO-
3 uptake from the first system.
KW - (P. denitrificans)
KW - Denitrification
KW - Electron transport
KW - Nitrate uptake
KW - Proton translocation
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U2 - 10.1016/0005-2728(83)90049-X
DO - 10.1016/0005-2728(83)90049-X
M3 - Article
AN - SCOPUS:0001548565
SN - 0005-2728
VL - 723
SP - 415
EP - 427
JO - Biochimica et Biophysica Acta (BBA) - Bioenergetics
JF - Biochimica et Biophysica Acta (BBA) - Bioenergetics
IS - 3
ER -
