Phototrophic Fe(II) Oxidation Promotes Organic Carbon Acquisition by Rhodobacter capsulatus SB1003
Phototrophic Fe(II) Oxidation Promotes Organic Carbon Acquisition by Rhodobacter capsulatus SB1003
复制标题
光养 Fe(II) 氧化促进荚膜红杆菌 SB1003 获取有机碳
DOI：
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发表时间：
2007
影响因子：
4.4
通讯作者：
D. Newman
中科院分区：
文献类型：
--
作者：
N. Caiazza;D. Lies;D. Newman
摘要铁（Ⅱ）的光合氧化作用是铁基生态系统中的一种主要生产方式。在这项研究中，我们采用Rhodobacter capsulatus SB 1003作为模式生物来测试的假设，光合Fe（II）氧化可以耦合到有机碳的收购。R. capsulatus SB 1003在缺氧条件下以光依赖的方式氧化Fe（II），但未能在可溶性Fe（II）上生长。然而，当向菌株提供Fe（II）-柠檬酸盐时，观察到生长依赖于微生物催化的Fe（II）氧化，导致Fe（III）-柠檬酸盐的形成。随后的光化学分解的Fe（III）-柠檬酸产生乙酰乙酸，支持在光下生长，但不是黑暗中。编码乙酰乙酸利用所需的atoA和atoD同源物的基因（RRC 00247和RRC 00248）的缺失严重损害了R. capsulatus SB 1003在Fe（II）-柠檬酸盐上生长。R.在柠檬酸盐存在下，荚膜菌SB 1003的生长不能解释为通过配体的间接作用[如改变Fe（II）氧化的热力学或防止细胞结壳]在Fe（II）上的岩石自养生长。总之，这些结果表明，R。capsulatus SB 1003在Fe（II）-柠檬酸盐上光合异养生长。次氮基三乙酸也支持光依赖性生长的Fe（II），这表明，Fe（II）氧化可能是一个一般的机制，使一些Fe（II）氧化细菌矿山，否则难以获得的有机碳源。
ABSTRACT Anoxygenic phototrophic Fe(II) oxidation is usually considered to be a lithoautotrophic metabolism that contributes to primary production in Fe-based ecosystems. In this study, we employed Rhodobacter capsulatus SB1003 as a model organism to test the hypothesis that phototrophic Fe(II) oxidation can be coupled to organic carbon acquisition. R. capsulatus SB1003 oxidized Fe(II) under anoxic conditions in a light-dependent manner, but it failed to grow lithoautotrophically on soluble Fe(II). When the strain was provided with Fe(II)-citrate, however, growth was observed that was dependent upon microbially catalyzed Fe(II) oxidation, resulting in the formation of Fe(III)-citrate. Subsequent photochemical breakdown of Fe(III)-citrate yielded acetoacetic acid that supported growth in the light but not the dark. The deletion of genes (RRC00247 and RRC00248) that encode homologs of atoA and atoD, required for acetoacetic acid utilization, severely impaired the ability of R. capsulatus SB1003 to grow on Fe(II)-citrate. The growth yield achieved by R. capsulatus SB1003 in the presence of citrate cannot be explained by lithoautotrophic growth on Fe(II) enabled by indirect effects of the ligand [such as altering the thermodynamics of Fe(II) oxidation or preventing cell encrustation]. Together, these results demonstrate that R. capsulatus SB1003 grows photoheterotrophically on Fe(II)-citrate. Nitrilotriacetic acid also supported light-dependent growth on Fe(II), suggesting that Fe(II) oxidation may be a general mechanism whereby some Fe(II)-oxidizing bacteria mine otherwise inaccessible organic carbon sources.
影响因子：
2.7
作者：
R. Elble
通讯作者：
R. Elble
影响因子：
15
作者：
Barbeau, K;Zhang, GP;Butler, A
通讯作者：
Butler, A