Abstract
The habitat distribution of iron-oxidizing bacteria in the lower reaches of Tamagawa hot spring was investigated as a preliminary study to develop an advanced neutralization technique for acidic river water in the region. First, the 16S rRNA nucleotide sequences of the bacteria isolated from river water in this stream area were analyzed. It was confirmed that the inclusion of acidophilic iron-oxidizing bacteria showed 100% homology with Acidithiobacillus ferrooxidans. Water samples were collected from 8 spots selected in the region relatively close to the neutralization plant. The number of bacteria was determined by the most probable number (MPN) method. From a correlation analysis between pH and the number of bacteria, the 8 spots were classified into four groups. In the spots, classified as the Yukawa-Shibukuro region, it was found that the water is quite acidic at a pH=2-3 and that the number of bacteria was relatively large at 104-105 [MPN · 100 ml-1].
