Studies of Radioresistant Thermophilic Bacteria from Geothermal Areas in Taiwan
Date Issued
2005
Date
2005
Author(s)
Hsu, Chia-Ju
DOI
zh-TW
Abstract
There are many different kinds of thermophilic bacteria living in the geothermal environment around Taiwan. According to the phylogenetic analysis, the well documented radiation resistant Deinococcus radiodurans and thermophilic bacteria Thermus spp. may come from same ancestor. Several thermophilic bacteria with extremely gamma-radiation resistance had been reported from hot spring environment recently. The objective of this study is to investigate thermophilic bacteria also carrying radio-resistant ability from hot springs in Taiwan. Two hundred and three thermophiles were isolated from 72 hot springs in Taiwan after gamma radiation treatment of the samples. According to 16S rDNA sequence analysis, these isolates were grouped into 7 genera: Deioncoccus spp., Rubrobacter spp., Meiothermus spp., Bacillus spp., Aneurinibacillus spp., Anoxybacillus spp. and Paenibacillus spp. Twenty strains were selected for further studies. Besides the morphological, biochemical and genetic analyses of these twenty isolates, the stress conditions including γ and UV radiation, heavy metal ﹝Cd(NO3)2 & HgCl2﹞ as well as hydrogen peroxide treatment are also determined. The results showed that most of the isolates were extremely resistant to γ-radiation, UV light as well as hydrogen peroxide. However, there are no evidence to show that these thermophilic radioresistant bacteria also have the ability to resistant heavy metal. This is the first report that Meiothermus spp., Aneurinibacillus spp., Anoxybacillus spp. and Paenibacillus spp. have the ability to resist radiation.
Subjects
嗜熱菌
輻射抗性
Thermophilic Bacteria
Radioresistant
Type
other