Orenia metallireducens sp nov Strain Z6, a Novel Metal- Reducing Member of the Phylum Firmicutes from the Deep Subsurface
Orenia metallireducens sp nov Strain Z6, a Novel Metal- Reducing Member of the Phylum Firmicutes from the Deep Subsurface
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DOI：
10.1128/aem.02382-16
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发表时间：
2016-11-01
影响因子：
4.4
通讯作者：
Fouke, Bruce W.
中科院分区：
文献类型：
--
作者：
Dong, Yiran;Sanford, Robert A.;Fouke, Bruce W.
一种新的嗜盐和金属还原细菌，Orenia metallerucens菌株Z6，分离自2.02公里深的钻孔在伊利诺伊州盆地，IL的咸水地下水提取。这种生物共享96%的16 S rRNA基因的相似性与Orenia marismortui，但表现出生理特性，以前未知的本属。除了表现出奥雷尼亚属典型的发酵代谢外，菌株Z6还使用H-2作为电子供体还原各种金属氧化物[Fe（III）、Mn（IV）、Co（III）和Cr（VI）]。菌株Z6在pH值（6至9.6）、盐度（0.4至3.5M NaCl）和温度（20至60 ℃）的宽范围内积极还原水铁矿。在pH 6.5时，菌株Z6还还原更多的结晶铁氧化物，例如纤铁矿（γ-FeOOH）、针铁矿（α-FeOOH）和赤铁矿（α-Fe 2 O3）。X射线吸收精细结构（XAFS）的分析后，Fe（III）的还原菌株Z6显示光谱从铁的次生矿物相一致的蓝铁矿[Fe-3（PO 4）（2）]和菱铁矿（FeCO 3）的沉淀。Z6菌株的基因组草图大小为3.47 Mb，包含3，269个蛋白质编码基因。与众所周知的铁还原希瓦氏菌和吉伯氏菌不同，这种生物缺乏典型的Fe（III）还原的C型细胞色素。菌株Z6代表了被报道还原三价铁矿物和其他金属氧化物的Orenia属（Halanaerobiales目）中的第一个细菌物种。这种微生物扩大了已知栖息在深层地下的铁还原微生物的系统发育和生理范围，并提出了微生物铁还原的新机制。这些区别于其他Orenia spp。支持将菌株Z6命名为新物种，Orenia metalliducens sp. nov.。重要的是新的铁还原物种，Orenia metalliducens sp. nov.，Z6菌株是从位于美国伊利诺斯盆地陆地表面以下2.02km的地质构造收集的地下水中分离的。对菌株Z6的系统发育、生理和基因组分析发现，它具有独特的铁还原剂特性，包括（i）在宽温度范围内的活性微生物铁还原能力（20至60摄氏度），pH值（6至9.6），以及盐度（0.4至3.5MNaCl），（ii）缺乏C型细胞色素通常与铁还原在Gebelum和希瓦氏菌属物种，和（iii）是唯一能够还原结晶针铁矿和赤铁矿的盐藻目成员。这项研究扩大了铁还原微生物的系统发育关系，代谢能力和催化机制的范围。
A novel halophilic and metal-reducing bacterium, Orenia metallireducens strain Z6, was isolated from briny groundwater extracted from a 2.02 km-deep borehole in the Illinois Basin, IL. This organism shared 96% 16S rRNA gene similarity with Orenia marismortui but demonstrated physiological properties previously unknown for this genus. In addition to exhibiting a fermentative metabolism typical of the genus Orenia, strain Z6 reduces various metal oxides [Fe(III), Mn(IV), Co(III), and Cr(VI)], using H-2 as the electron donor. Strain Z6 actively reduced ferrihydrite over broad ranges of pH (6 to 9.6), salinity (0.4 to 3.5M NaCl), and temperature (20 to 60 degrees C). At pH 6.5, strain Z6 also reduced more crystalline iron oxides, such as lepidocrocite (gamma-FeOOH), goethite (alpha-FeOOH), and hematite (alpha-Fe2O3). Analysis of X-ray absorption fine structure (XAFS) following Fe(III) reduction by strain Z6 revealed spectra from ferrous secondary mineral phases consistent with the precipitation of vivianite [Fe-3(PO4)(2)] and siderite (FeCO3). The draft genome assembled for strain Z6 is 3.47 Mb in size and contains 3,269 protein-coding genes. Unlike the well-understood iron-reducing Shewanella and Geobacter species, this organism lacks the c-type cytochromes for typical Fe(III) reduction. Strain Z6 represents the first bacterial species in the genus Orenia (order Halanaerobiales) reported to reduce ferric iron minerals and other metal oxides. This microbe expands both the phylogenetic and physiological scopes of iron-reducing microorganisms known to inhabit the deep subsurface and suggests new mechanisms for microbial iron reduction. These distinctions from other Orenia spp. support the designation of strain Z6 as a new species, Orenia metallireducens sp. nov.IMPORTANCEA novel iron-reducing species, Orenia metallireducens sp. nov., strain Z6, was isolated from groundwater collected from a geological formation located 2.02 km below land surface in the Illinois Basin, USA. Phylogenetic, physiologic, and genomic analyses of strain Z6 found it to have unique properties for iron reducers, including (i) active microbial iron-reducing capacity under broad ranges of temperatures (20 to 60 degrees C), pHs (6 to 9.6), and salinities (0.4 to 3.5MNaCl), (ii) lack of c-type cytochromes typically affiliated with iron reduction in Geobacter and Shewanella species, and (iii) being the only member of the Halanaerobiales capable of reducing crystalline goethite and hematite. This study expands the scope of phylogenetic affiliations, metabolic capacities, and catalytic mechanisms for iron-reducing microbes.