阳离子对耐辐射奇球菌对放射性铯生物吸收的影响(英文)

耐辐射奇球菌能够耐受高剂量的辐射,促使人们考虑利用此特性进行放射性核素和有毒化学品的生物修复。但是,有关耐辐射奇球菌对放射性铯的生物吸收却未见报道。本文研究了耐辐射奇球菌对放射性铯的生物吸收及其他阳离子对其生物吸收的影响。在平衡状态时,耐辐射奇球菌对放射性铯的最大吸收量为2100kBq/kg(鲜重)。在供试的一价阳离子中,NH4+对其生物吸收的拮抗作用最强,但是只有当NH4+的浓度超过100mmol/L时,这种拮抗作用才比较明显。二价阳离子,如Ca2+和Pb2+也能降低耐辐射奇球菌对放射性铯的吸收。Al3+和Cr3+对耐辐射奇球菌具有较强的细胞毒性,当其浓度超过1mmol/L时,耐辐射奇球菌的生长就完全被抑制。

BIOSORPTION OF RADIOCESIUM BY Deinococcus radiodurans(INFLUENCED BY CATIONS

Deinococcus radiodurans has a strong ability to withstand high doses of radiation,which makes it as an ideal candidate for bioremediation of sites contaminated with radionuclides and toxic chemicals.However,no data is available on whether D.radiodurans has a specific sorption capacity to radiocesium for bioremediation purpose.The radiocesium biosorption capacity of live cells of D.radiodurans in the presence of other interfering cations was investigated.The maximum biosorption capacity of radiocesium by D.radiodurans in equilibrium state was about 2,100 kBq/kg(fresh weight basis).Among the tested monovalent cations,NH _4 had the strongest antagonism on 134Cs biosorption for D.radiodurans.However,this antagonism could only be observed at a concentration as high as 100 mmol/L.Divalent cations,such as Ca2 and Pb2 could reduced the biosorption of radiocesium by D.radiodurans.Al3 and Cr3 were cytotoxic to D.radiodurans cells,the growth of D.radiodurans cells was inhibited when the concentrations of these cations were greater than 1 mmol/L.