Screening Isolation and Characterization of Thermophilic and Acidophilic Bacteria

We have isolated 53 thermophilic and acidophilic bacteria from about 150 samples from acidic hot springs. All the strains isolated exhibited growth only at high temperatures and low pH ranges. We extensively characterized the strain UZ-1 which was isolated from Unzen spa. This strain was found to be a gram-negative, aerobic and heterotrophic bacterium. The DNA base composition was 63 mol% GC. Growth occurs over a range of 37℃ to 65℃ with an optimum temperature of 60℃, and between pH 2.0 and pH 6.0 with an optimum pH of 3.0. On the other hand, the optimum temperature of the other 6 isolated strains was 70℃. We report, in this paper, the characteristics of the isolated strains.