Ferrimicrobium acidiphilum gen. nov., sp nov and Ferrithrix thermotolerans gen. nov., sp nov.: heterotrophic, iron-oxidizing, extremely acidophilic actinobacteria
Ferrimicrobium acidiphilum gen. nov., sp nov and Ferrithrix thermotolerans gen. nov., sp nov.: heterotrophic, iron-oxidizing, extremely acidophilic actinobacteria
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DOI：
10.1099/ijs.0.65409-0
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发表时间：
2009-05-01
影响因子：
2.8
通讯作者：
Hallberg, Kevin B.
中科院分区：
文献类型：
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作者：
Johnson, D. Barrie;Bacelar-Nicolau, Paula;Hallberg, Kevin B.
分离出了两种新的极端嗜酸、铁氧化放线菌，一种来自英国北威尔士的一个矿区（菌株T23(T)），另一种来自美国怀俄明州黄石国家公园的一个地热区（Y005(T)）。这些新的放线菌属于酸微菌亚纲，与该亚纲中唯一的其他已分类成员（嗜酸微菌属的嗜酸铁氧化菌）不同，这两种菌株都是专性异养菌。矿区菌株是中温菌，呈小杆状生长，而黄石菌株是中等嗜热菌，呈长丝状生长，在液体培养基中形成肉眼可见的絮状物。两种菌株在添加酵母提取物的培养物中都加速了黄铁矿的氧化溶解，但都不能氧化还原态的硫。亚铁氧化提高了新的中温放线菌T23(T)的生长产量，不过这一点在黄石菌株中未得到证实。两种菌株在无氧培养基中都能以甘油作为电子供体催化三价铁的异化还原。基于对它们染色体DNA碱基组成以及16S rRNA基因序列的比较分析，这两种菌株彼此不同，且与嗜酸微菌属的嗜酸铁氧化菌也不同，是两个新属的代表。分别为中温菌株和中等嗜热菌株提出了新属名嗜酸铁微菌属（Ferrimicrobium acidiphilum gen. nov.），新种名嗜酸铁微菌（Ferrimicrobium acidiphilum sp. nov.）以及耐热铁丝菌属（Ferrithrix thermotolerans gen. nov.），新种名耐热铁丝菌（Ferrithrix thermotolerans sp. nov.），其相应的模式菌株分别为T23(T)（=DSM 19497(T) = ATCC BAA - 1647(T)）和Y005(T)（=DSM 19514(T) = ATCC BAA - 1645(T)）
Two novel extremely acidophilic, iron-oxidizing actinobacteria were isolated, one from a mine site in North Wales, UK (isolate T23(T)), and the other from a geothermal site in Yellowstone National Park, Wyoming, USA (Y005(T)). These new actinobacteria belong to the subclass Acidimicrobidae, and in contrast to the only other classified member of the subclass (Acidimicrobium ferrooxidans), both isolates were obligate heterotrophs. The mine site isolate was mesophilic and grew as small rods, while the Yellowstone isolate was a moderate thermophile and grew as long filaments, forming macroscopic flocs in liquid media. Both isolates accelerated the oxidative dissolution of pyrite in yeast extract-amended cultures, but neither was able to oxidize reduced forms of sulfur. Ferrous iron oxidation enhanced growth yields of the novel mesophilic actinobacterium T23(T) though this was not confirmed for the Yellowstone isolate. Both isolates catalysed the dissimilatory reduction of ferric iron, using glycerol as electron donor, in oxygen-free medium. Based on comparative analyses of base compositions of their chromosomal DNA and of their 16S rRNA gene sequences, the isolates are both distinct from each other and from Acidimicrobium ferrooxidans, and are representatives of two novel genera. The names Ferrimicrobium acidiphilum gen. nov., sp. nov. and Ferrithrix thermotolerans gen. nov., sp. nov. are proposed for the mesophilic and moderately thermophilic isolates, respectively, with the respective type strains T23(T) (=DSM 19497(T) ATCC BAA-1647(T)) and Y005(T) (=DSM 19514(T) = ATCC BAA-1645(T)).