Enzymatic manganese(II) oxidation by a marine α-proteobacterium
Enzymatic manganese(II) oxidation by a marine α-proteobacterium
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DOI：
10.1128/aem.67.9.4024-4029.2001
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发表时间：
2001-09-01
影响因子：
4.4
通讯作者：
Tebo, BM
中科院分区：
文献类型：
--
作者：
Francis, CA;Co, EM;Tebo, BM
根据其将可溶性 Mn(II) 氧化为不溶性 Mn(III, IV) 氧化物的能力，从加利福尼亚州圣地亚哥圣地亚哥湾的表面沉积物中分离出一种黄色海洋细菌，指定为菌株 SD-21。 16S rRNA 分析表明，该生物体与 Etythrobacter 属的成员关系最密切，Etythrobacter 是变形菌门 α -4 亚组（α -4 Proteobacteria）内的需氧无氧光养细菌。然而，SD-21 具有许多与红杆菌属物种相关的显着表型特征，包括氧化 Mn(II) 的能力。在对数生长阶段，该生物体产生约 250 和 150 kDa 的 Mn(II) 氧化因子，这些因子对热不稳定并被叠氮化物和邻菲咯啉抑制，表明金属酶的参与。尽管Mn(II)氧化酶的表达不依赖于Mn(II)的存在，但在培养基中与Mn(II)一起孵育的培养物中达到了更高的总体生长产量。此外，在光照下生长的培养物中，Mn(II) 氧化速度似乎较慢。这是 α -4 变形菌内 Mn(II) 氧化的首次报道，也是在海洋革兰氏阴性细菌中鉴定出的第一个 Mn(II) 氧化蛋白。
A yellow-pigmented marine bacterium, designated strain SD-21, was isolated from surface sediments of San Diego Bay, San Diego, Calif., based on its ability to oxidize soluble Mn(II) to insoluble Mn(Ill, IV) oxides. 16S rRNA analysis revealed that this organism was most closely related to members of the genus Etythrobacter, aerobic anoxygenic phototrophic bacteria within the alpha -4 subgroup of the Proteobacteria (alpha -4 Proteobacteria). SD-21, however, has a number of distinguishing phenotypic features relative to Erythrobacter species, including the ability to oxidize Mn(II). During the logarithmic phase of growth, this organism produces Mn(II)-oxidizing factors of approximate to 250 and 150 kDa that are heat labile and inhibited by both azide and o-phenanthroline, suggesting the involvement of a metalloenzyme. Although the expression of the Mn(II) oxidase was not dependent on the presence of Mn(II), higher overall growth yields were reached in cultures incubated with Mn(ll) in the culture medium. In addition, the rate of Mn(II) oxidation appeared to be slower in cultures grown in the light. This is the first report of Mn(II) oxidation within the alpha -4 Proteobacteria as well as the first Mn(Il)-oxidizing proteins identified in a marine gram-negative bacterium.