权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Training of Iron-oxidizing Bacteria Capable of Oxidizing Ferrous Ion at pH below 1

能够在 pH 值低于 1 时氧化亚铁离子的铁氧化细菌的培养

基本信息

批准号：
61550460
负责人：
KOUNOSU Akira
金额：
$ 1.09万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

It's been believed that the autotrophic iron-oxidizing bacterium Thiobacillus ferrooxidans cannot grow at pH below 1.4. The objective of this project was to train bacteria capable of oxidizing ferrous ions at pH below 1.0 and to study its character for oxidation of the substrate. For training acid-resistant iron-oxidizing bacteria, it was assumed that the transmissible plasmid of Thiobacillus thiooxidans, a sulfur-oxidizing bacterium which can grow at pH as low as 0.5, could be transmitted to T. ferrooxidans , and T. ferrooxidans might assume the acid-resistance encoded on the plasmid. At first, a culture consisting mainly of T. thiooxidans and T. ferrooxidans was subcultured repeatedly with elemental sulfur as energy source so that it got to oxidize sulfur at pH below 1.0. Then, the microorganisms were cultured at initial pH 0.6 with ferrous ions as energy source, and it was observed that ferros ions were oxidized and ion-oxidizing bactera grew. There-fore, it was speculated that transmission of plasmid had occured from T. thiooxidans to T. ferrooxidans, and in consequence, T. ferrooxidans which had assumed the acid-resistance of T. thiooxidans had grown and oxidized the ferrous ions at pH below 1.0. Several months later, however,when the acid-resistant ion-oxidizing bacteria above were cultured with ferrous ions at initial pH 0.6, ion-oxidizing bacteria showed little growth in the case no elemental sulfur was added to the medium, while active growth and ion oxidation was observed with elemental sulfur added. Moreover, in experiments in which bacteria which were enrichment-cultured either with elemental sulfur or ferrous ions as energy source were cultured at initial pH 0.6 with ferrous ions, ion-oxidizing bacteria grew and oxidized the ferrous ions if elemental sulfur was added to the medium. Thus, it is suggested that elemental sulfur itself is engaged directly in T. ferrooxidans' assuming acid-resistance apart from plasmid of T.thiooxidans.

据认为，自养铁氧化细菌氧化亚铁硫杆菌在 pH 值低于 1.4 时无法生长。该项目的目的是培养能够在 pH 值低于 1.0 时氧化亚铁离子的细菌，并研究其底物氧化特性。为了训练耐酸铁氧化细菌，假设可以将氧化硫硫杆菌（一种可以在低至0.5的pH下生长的硫氧化细菌）的可传播质粒传递给氧化亚铁硫杆菌，并且氧化亚铁硫杆菌可能呈现出质粒上编码的耐酸性。首先，将主要由氧化硫硫杆菌和氧化亚铁杆菌组成的培养物以元素硫为能源进行反复传代培养，使其在pH低于1.0时氧化硫。然后，以亚铁离子为能源，在初始pH 0.6下培养微生物，观察到亚铁离子被氧化并且离子氧化细菌生长。因此，推测发生了从氧化硫硫杆菌向氧化亚铁杆菌的质粒传递，其结果是，氧化硫硫杆菌具有耐酸性的氧化亚铁杆菌生长，并在pH低于1.0时氧化亚铁离子。然而几个月后，当上述耐酸离子氧化菌在初始pH 0.6下与亚铁离子一起培养时，在培养基中不添加元素硫的情况下离子氧化菌几乎没有生长，而添加元素硫则观察到活跃的生长和离子氧化。此外，在将用元素硫或亚铁离子作为能源进行富集培养的细菌在初始pH 0.6下用亚铁离子培养的实验中，如果将元素硫添加到培养基中，则离子氧化细菌生长并氧化亚铁离子。因此，表明除了氧化亚铁硫杆菌的质粒之外，元素硫本身也直接参与氧化亚铁硫杆菌的耐酸性。