Cesium accumulation by bacterium Thermus sp. TibetanG7:hints for biomineralization of cesium-bearing geyserite in hot springs in Tibet,China  

作　　者：WANG HaiLei1,2,3, ZHENG MianPing1,2,3 & HUANG XiaoXing4 1 Institute of Mineral Resources, Chinese Academy of Geological Sciences (CAGS), Beijing 100037, China 2 R&D Center for Saline Lake and Epithermal Deposits, CAGS, Beijing 100037, China 3 Open Laboratory of Saline Lake Resourses and Environment, CAGS, Beijing 100037, China 4 Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100081, China 

出　　处：《Chinese Science Bulletin》2007年第19期2680-2686,共7页

基　　金：the China Geological Survey (contract No. 200313000065) ;the State Plan for Development of Basic Research in Key Areas (contract No. 2002CG412610)

摘　　要：The bacterium Thermus sp. TibetanG7, isolated from hot springs in Tibet, China, was examined for the ability to accumulate cesium from solutions. Environmental conditions were simulated and the effects of pH, K+, Na+ and K+-regimes were then studied to determine the possible role of the bacterium in the formation of cesium-bearing geyserite around these hot springs. In despite of the inhibition of K+ and Na+, the bacterium Thermus sp. TibetanG7 revealed noticeable accumulation of cesium from solutions, with maximum accumulations of 53.49 and 40.41 μmol Cesium/g cell dry weight in Na+ and K+ inhibition experiments, respectively. The accumulation of cesium by this microorganism is rapid, with 40%―50% accumulated within the first 5 min. K+-deficient cells showed a much higher capacity of cesium accu- mulation compared with K+-sufficient cells. It is evident that the bacteria within the genus thermus play a significant role in the cesium assembly. The formation of cesium-bearing geyserite is also considered.The bacterium Thermus sp. TibetanG7, isolated from hot springs in Tibet, China, was examined for the ability to accumulate cesium from solutions. Environmental conditions were simulated and the effects of pH, K^＋, Na^＋and K^＋-regimes were then studied to determine the possible role of the bacterium in the formation of cesium-bearing geyserite around these hot springs. In despite of the inhibition of K^＋ and Na^＋, the bacterium Thermus sp. TibetanG7 revealed noticeable accumulation of cesium from solutions, with maximum accumulations of 53.49 and 40.41 pmol Cesium/g cell dry weight in Na^＋ and K^＋ inhibition experiments, respectively. The accumulation of cesium by this microorganism is rapid, with 40% --50% accumulated within the first 5 min. K^＋-deficient cells showed a much higher capacity of cesium accumulation compared with K^＋-sufficient cells. It is evident that the bacteria within the genus thermus play a significant role in the cesium assembly. The formation of cesium-bearing geyserite is also considered.

关 键 词：铯元素 沉积物 硅华 生物矿化 

分 类 号：Q93[生物学—微生物学]