Isolation and characterization of a genetically tractable photo autotrophic Fe(II)-oxidizing bacterium, Rhodopseudomonas palustris strain TIE-1
Isolation and characterization of a genetically tractable photo autotrophic Fe(II)-oxidizing bacterium, Rhodopseudomonas palustris strain TIE-1
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DOI：
10.1128/aem.71.8.4487-4496.2005
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发表时间：
2005-08-01
影响因子：
4.4
通讯作者：
Newman, DK
中科院分区：
文献类型：
--
作者：
Jiao, YYQ;Kappler, A;Newman, DK
我们报告的分离和表征的光养亚铁[Fe（II）] -氧化细菌命名为TIE-1，不同于其他Fe（II）-氧化光养生物，因为它是遗传上听话。在厌氧条件下，TIE-1生长photoautotrophically与Fe（II），H-2，或硫代硫酸盐作为电子供体和photoheterotrophically与各种有机碳源。TIE-1也在黑暗中以化学异养方式生长。根据生理和系统发育分析，该菌株可能是一个新的紫色非硫细菌种沼泽红球藻。Fe（II）氧化在pH 6.5至6.9时最佳。Fe（II）氧化的矿物产物是pH依赖性的：低于pH 7.0针铁矿（α-FeOOH）形式，和高于pH 7.2磁铁矿（Fe 3 O 4）形式。TIE-1在琼脂平板上形成菌落，对多种抗生素敏感。过度活跃的mariner转座子能够以类似于10（-5）的转座频率随机插入染色体中。为了鉴定参与光养Fe（II）氧化的组分，通过转座子诱变产生TIE-1的突变体，并在细胞悬浮测定中筛选Fe（II）氧化的缺陷。在筛选的约12，000个突变体中，鉴定出6个在Fe（II）氧化中特异性受损。这些突变体中的五个在一个基因中具有独立的破坏，该基因被预测为编码似乎是ABC转运系统的一部分的整合膜蛋白;第六个突变体在一个基因中具有插入，该基因是CobS的同源物，CobS是一种参与钴胺素（维生素B-12）生物合成的酶。
We report the isolation and characterization of a phototrophic ferrous iron [Fe(II)] -oxidizing bacterium named TIE-1 that differs from other Fe(II)-oxidizing phototrophs in that it is genetically tractable. Under anaerobic conditions, TIE-1 grows photoautotrophically with Fe(II), H-2, or thiosulfate as the electron donor and photoheterotrophically with a variety of organic carbon sources. TIE-1 also grows chemoheterotrophically in the dark. This isolate appears to be a new strain of the purple nonsulfur bacterial species Rhodopseudomonas palustris, based on physiological and phylogenetic analysis. Fe(II) oxidation is optimal at pH 6.5 to 6.9. The mineral products of Fe(II) oxidation are pH dependent: below pH 7.0 goethite (alpha-FeOOH) forms, and above pH 7.2 magnetite (Fe3O4) forms. TIE-1 forms colonies on agar plates and is sensitive to a variety of antibiotics. A hyperactive mariner transposon is capable of random insertion into the chromosome with a transposition frequency of similar to 10(-5). To identify components involved in phototrophic Fe(II) oxidation, mutants of TIE-1 were generated by transposon mutagenesis and screened for defects in Fe(II) oxidation in a cell suspension assay. Among approximately 12,000 mutants screened, 6 were identified that are specifically impaired in Fe(II) oxidation. Five of these mutants have independent disruptions in a gene that is predicted to encode an integral membrane protein that appears to be part of an ABC transport system; the sixth mutant has an insertion in a gene that is a homolog of CobS, an enzyme involved in cobalamin (vitamin B-12) biosynthesis.