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首页> 外文期刊>Applied Microbiology >Bacteriology of Manganese Nodules IV. Induction of an MnO2-Reductase System in a Marine Bacillus
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Bacteriology of Manganese Nodules IV. Induction of an MnO2-Reductase System in a Marine Bacillus

机译：锰结核的细菌学IV。海水杆菌中MnO2-还原酶系统的诱导

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Bacillus 29, isolated from a ferromanganese nodule from the Atlantic Ocean, was shown to possess an MnO2-reductase system which is induced in the presence of manganous ion. Maximal activity of the enzyme system was induced in about 5 hr in the presence of 4.35 mm MnSO4 and was minimally dependent on the presence of either glucose or peptone and oxygen. Induction of optimal activity required the simultaneous presence of glucose and peptone. At least 30% of maximal activity was induced in 5 hr in the presence of 0.4 μm MnSO4. Actinomycin D (5 μg/ml) or chloramphenicol (35 μg/ml), when added to the induction medium, inhibited approximately 90% of MnO2-reductase synthesis and incorporation of uracil-2-14C or leucine-1-14C. Cell-free extracts having MnO2-reductase activity were prepared by sonic disruption of cell suspensions of induced Bacillus 29. Such extracts used glucose metabolism as a source of electrons. They had an average specific activity of 1.15 nmoles of MnII produced per mg of protein per hr at 25 C. They had a temperature optimum of 18 C for reductase activity and retained 50% of their activity at 4 C, the approximate temperature of the natural habitat of the organism. Extracts were stable for several days at 4 C but rapidly lost over 50% of their activity on freezing and thawing. Over 90% of the activity of the extract could be destroyed by heating in a boiling-water bath for 5 min. At a concentration of 1 mm, HgCl2 and atebrine dihydrochloride inhibited MnO2-reductase activity by at least 50%, but sodium azide was ineffective. The MnO2-reductase activity of induced cells and extracts from them was no greater in the absence of oxygen than in its presence, confirming an earlier observation that MnO2 and O2 do not compete as terminal electron acceptors in the respiratory activity of this organism.
机译：从来自大西洋的锰铁结核中分离的芽孢杆菌29被证明具有MnO2-还原酶系统，该系统在锰离子存在下被诱导。在存在4.35 mm MnSO4的情况下，在约5小时内诱导了酶系统的最大活性，并且最小程度地依赖于葡萄糖或蛋白ept和氧气的存在。诱导最佳活性需要同时存在葡萄糖和蛋白ept。在存在0.4μmMnSO4的情况下，在5小时内诱导出至少30％的最大活性。当放线菌素D（5μg/ ml）或氯霉素（35μg/ ml）添加到诱导培养基中时，抑制了大约90％的MnO2-还原酶合成以及尿嘧啶2-14C或亮氨酸1-14C的掺入。通过对诱导的芽孢杆菌29的细胞悬浮液进行声波破碎来制备具有MnO 2-还原酶活性的无细胞提取物。这种提取物使用葡萄糖代谢作为电子源。它们在25°C下的平均比活性为每毫克蛋白质每小时产生的MnII 1.15毫摩尔。对于还原酶活性，它们的最适温度为18°C，并在4°C下保持了50％的活性，这是大约25℃的温度。有机体的自然栖息地。提取物在4 C下稳定几天，但在冷冻和解冻后迅速丧失超过50％的活性。在沸水浴中加热5分钟会破坏提取物90％以上的活性。在1 mm的浓度下，HgCl2和盐酸二乙苯特胺抑制MnO2-还原酶活性至少50％，但叠氮化钠无效。在无氧条件下，诱导细胞及其提取物的MnO2-还原酶活性并不比在有氧条件下高，这证实了较早的观察结果，即MnO2和O2在该生物体的呼吸活动中不作为末端电子受体竞争。

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