Involvement of microaerophilic iron-oxidizing bacteria in the iron-oxidizing process at the surface layer of flooded paddy field soil
Involvement of microaerophilic iron-oxidizing bacteria in the iron-oxidizing process at the surface layer of flooded paddy field soil
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DOI：
10.1007/s11368-020-02717-w
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发表时间：
2020-07
影响因子：
3.6
通讯作者：
Koki Nakagawa;J. Murase;S. Asakawa;Takeshi Watanabe
中科院分区：
文献类型：
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作者：
Koki Nakagawa;J. Murase;S. Asakawa;Takeshi Watanabe
目的探讨微需氧铁氧化细菌（FeOB）是否参与淹水稻田土壤中缺氧-好氧界面的铁氧化过程，研究了淹水水稻土微宇宙表层中与Galionella相关的FeOB和微需氧Fe（II）氧化剂Ferrigenium kumadai An 22氧化Fe（II）的O2条件，材料与方法淹水水稻土微宇宙培养30 d。培养后，从土壤表面以2 mm的间隔对5个土层进行取样。采用qPCR和DGGE方法分析了与Gallionella相关的FeOB的群落结构。在培养实验中，测定了F. kumadai An 22接种和未接种的凝胶稳定梯度管进行分析，其中O2和Fe（II）形成相反的梯度。在0-2 mm土层中，与Galionella相关的FeOB的16 S rRNA基因拷贝数最高。DGGE分析表明，几个来自Galionella相关的FeOB新出现的高强度的表层土壤带。在培养试验中，F. kumadai A22生长在好氧侧的缺氧-缺氧界面与铁oxides.ConclusionThe本研究表明，Gallionella相关的微需氧FeOB增殖在表层的淹水稻田土壤，推测通过氧化Fe（II）在缺氧-缺氧界面。
PurposeTo reveal whether microaerophilic Fe (II)-oxidizing bacteria (FeOB) participate in the Fe (II) oxidation at the oxic-anoxic interface in flooded paddy field soil, distribution of microaerophilic FeOB belonging to Gallionellaceae (Gallionella-related FeOB) in the surface layer of a flooded paddy soil microcosm and O 2 conditions for the Fe (II) oxidation by a microaerophilic Fe (II) oxidizer, Ferrigenium kumadai An22, were investigated.Materials and methodsFlooded paddy soil microcosms were incubated for 30 days. Five soil layers were sampled at 2-mm intervals from the soil surface after the incubation. The community structure of Gallionella-related FeOB was analyzed with qPCR and DGGE methods. In the culture experiment, O 2 and Fe (II) profiles in F. kumadai An22-inoculated and non-inoculated gel-stabilized gradient tubes were analyzed, in which an opposing gradient of O 2 and Fe (II) was formed.ResultsA thin oxic layer was formed at the soil surface after the incubation. The copy number of 16S rRNA genes of Gallionella-related FeOB was highest at the top 0–2 mm layer of the soil. DGGE analysis showed that several bands derived from Gallionella-related FeOB newly appeared at the top soil layer with high intensity. In the culture experiment, F. kumadai A22 grew at the oxic side of the oxic-anoxic interface with the formation of Fe oxides.ConclusionThe present study indicated that Gallionella-related microaerophilic FeOB proliferated in the surface layer of flooded paddy field soil, presumably by oxidizing Fe (II) in the oxic-anoxic interface.