METABOLISM OF HYDROXYLAMINE TO NITRITE BY NITROSOMONAS
METABOLISM OF HYDROXYLAMINE TO NITRITE BY NITROSOMONAS
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DOI：
10.1042/bj0910008
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发表时间：
1964-01-01
影响因子：
4.1
通讯作者：
ANDERSON, JH
中科院分区：
文献类型：
--
作者：
ANDERSON, JH
洗过的细胞悬浮液的自养亚硝化单胞菌，获得其自由能的增长从NH3的氧化为亚硝酸盐，迅速氧化低浓度的NH3和羟胺，但不是次硝酸盐亚硝酸盐。提取物从羟胺产生少量亚硝酸盐，但从NH3不产生亚硝酸盐。在厌氧条件下，在提取物和亚甲基蓝的存在下，羟胺消失，并形成了可忽略不计的亚硝酸盐。产生的一氧化氮和一氧化二氮的量相当于所加入的羟胺。在好氧条件下，以亚甲基蓝或哺乳动物细胞色素C为载体的浸提物存在下，羟胺的消失速率和亚硝酸盐的产生增加。在细胞色素C存在下，羟胺的消失被氰化物抑制。在亚甲蓝存在下，氰化物中毒提取物代谢羟胺和亚硝酸盐出现。羟胺的代谢可能是一个两阶段过程。在第一阶段，羟胺脱氢为硝酰基，硝酰基分解为一氧化氮，并且可以进一步脱氢为一氧化氮。亚甲基蓝与还原态天然氢载体处于平衡状态，其氧化涉及细胞色素和细胞色素氧化酶。阶段2是通过需要O2的酶系统将一氧化氮转化为亚硝酸盐。需氧条件下硝酸盐代谢为亚硝酸盐可能涉及细胞色素。
Washed-cell suspensions of the autotrophe Nitrosomonas, which obtains its free energy for growth from the oxidation of NH3 to nitrite, rapidly oxidized low concentrations of NH3 and hydroxylamine, but not hyponitrite to nitrite. Extracts produce small amounts of nitrite from hydroxylamine but did not produce nitrite from NH3. Anaerobically in the presence of the extract and methylene-blue, hydroxylamine disappeared and negligible amounts of nitrite were formed. Nitric-oxide and nitrous-oxide were produced in amounts equivalent to the hydroxylamine added. Aerobically in the presence of extracts, methylene-blue or mammalian cytochrome-c as carrier, the rate of disappearance of hydroxylamine and the nitrite production increased. The disappearance of hydroxylamine in the presence of cytochrome-c was inhibited by cyanide. In the presence of methylene-blue, cyanide-poisoned extracts metabolized hydroxylamine and nitrite appeared. The metabolism of hydroxylamine may be a 2-stage process. In stage-1, hydroxylamine is dehydrogenated to nitroxyl which decomposed to nitrous-oxide and which could be further dehydrogenated to nitric-oxide. The oxidation of a reduced natural Hydrogen carrier, with which methylene-blue was in equilibrium, involved a cytochrome and cytochrome oxidase. Stage-2 was the conversion of nitric-oxide into nitrite by an enzyme system requiring O2. The metabolism of nitric to nitrite aerobically may involve a cytochrome.