de Vries W, van Berchum H, Stouthamer A H
Antonie Van Leeuwenhoek. 1984;50(1):63-73. doi: 10.1007/BF00404908.
Campylobacter sputorum subsp. bubulus contained hydrogenase activity after growth with lactate and nitrate and after growth with hydrogen and nitrate. After growth with hydrogen and nitrate a molar growth yield (g dry cells/mol hydrogen) of 5.6 was measured. Hydrogenase and nitrate reductase were membrane-bound enzymes. In cells with high hydrogenase activity the----H+/O,----H+/NO2- and----H+/NO3- values with hydrogen as the electron donor were 3.74, 2.61 and 4.36 respectively. In cells with low hydrogenase activity these values were 2.33, -0.86 and 1.31 respectively. These values and the stoichiometry of respiration-driven proton translocation (----H+/2e = 2) led to the conclusion that hydrogenase is located at the periplasmic side of the cytoplasmic membrane. In cells with low lactate dehydrogenase activity or low hydrogenase activity the reduction of nitrate to nitrite could be separated from the reduction of nitrite to ammonia. Positive----H+/NO3- values (between 0.9 and 1.7) with lactate or hydrogen as the electron donor were measured in these cells whereas----H+/ NO2- values were negative. From this result it was concluded that nitrate reductase is located at the cytoplasmic face of the cytoplasmic membrane. The results explain the previous observation that molar growth yields with nitrate were somewhat higher than those with nitrite.
唾液弯曲杆菌泡亚种在以乳酸盐和硝酸盐为底物生长后以及以氢气和硝酸盐为底物生长后均具有氢化酶活性。以氢气和硝酸盐为底物生长后，测得的摩尔生长产率（克干细胞/摩尔氢气）为5.6。氢化酶和硝酸盐还原酶是膜结合酶。在具有高氢化酶活性的细胞中，以氢气作为电子供体时，----H⁺/O、----H⁺/NO₂⁻和----H⁺/NO₃⁻的值分别为3.74、2.61和4.36。在具有低氢化酶活性的细胞中，这些值分别为2.33、-0.86和1.31。这些值以及呼吸驱动的质子转运化学计量比（----H⁺/2e = ）得出结论，氢化酶位于细胞质膜的周质侧。在乳酸脱氢酶活性低或氢化酶活性低的细胞中，硝酸盐还原为亚硝酸盐的过程可以与亚硝酸盐还原为氨的过程分开。在这些细胞中，以乳酸盐或氢气作为电子供体时，测得的----H⁺/NO₃⁻值为正值（在0.9和1.7之间），而----H⁺/NO₂⁻值为负值。从该结果得出结论，硝酸盐还原酶位于细胞质膜的细胞质面。这些结果解释了先前的观察结果，即以硝酸盐为底物时的摩尔生长产率略高于以亚硝酸盐为底物时的摩尔生长产率。
