Wilhelm R, Abeliovich A, Nejidat A
Institut für Chemie und Dynamik der Geosphäre 6, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
J Biochem. 1998 Oct;124(4):811-5. doi: 10.1093/oxfordjournals.jbchem.a022184.
Axenic cultures of the ammonia-oxidizing bacterium Nitrosomonas europaea were starved of ammonia (energy source) for up to 342 d. During this time the bacteria retained the ability to respond instantly to ammonia (1 mM) or hydroxylamine (0.1 mM) amendment by oxidizing it to nitrite without initial protein synthesis. In vivo, the ability to oxidize amended ammonia stayed almost constant during the starvation period, but a drop in the hydroxylamine oxidation rate (to 33%) was observed after 4 wk of starvation when exogenous hydroxylamine was supplied as sole energy source. In contrast, it has been shown that the level and in vitro activity of hydroxylamine oxidoreductase were not significantly affected during the starvation period. Only minor changes were detected between the protein patterns on one-dimensional SDS-PAGE of growing and starved cells. Thus, it is concluded that the activities of the energy-generating enzymes in N. europaea were not affected during long-term ammonia starvation.
将氨氧化细菌欧洲亚硝化单胞菌的无菌培养物在无氨（能源）的条件下饥饿培养长达342天。在此期间，这些细菌保留了在不进行初始蛋白质合成的情况下，通过将氨（1 mM）或羟胺（0.1 mM）氧化为亚硝酸盐，对其添加立即做出反应的能力。在体内，饥饿期间氧化添加氨的能力几乎保持不变，但当以外源羟胺作为唯一能源供应4周后，观察到羟胺氧化速率下降（至33%）。相比之下，已表明在饥饿期间羟胺氧化还原酶的水平和体外活性没有受到显著影响。在生长细胞和饥饿细胞的一维SDS-PAGE蛋白质图谱之间仅检测到微小变化。因此，可以得出结论，欧洲亚硝化单胞菌中产生能量的酶的活性在长期氨饥饿期间不受影响。
