γ辐照下土壤分离菌对Sr^(2+)吸附特性及其FTIR分析

FTIR Analysis of Sr^(2+) Biosorption by Bacillus spp.Strains Isolated from Soil Treated with γ-Ray Radiation

从四川盆地紫色土中分离获得一株革兰氏阳性细菌,对该菌株形态学及16S序列分析,初步鉴定属于芽孢杆菌属。本文主要分析了一定剂量γ辐照前后该菌株对Sr2+的吸附效果。结果显示:实验辐照条件对该菌株吸附Sr2+有一定抑制作用,主要表现为其对Sr2+吸附效率达到90%以上的平衡点出现时间比无辐照情况下延迟了1.5d出现,生长速率最大值出现延迟了0.5d。SEM分析发现辐照后菌体出现不规则变形,说明一定剂量γ辐照会对所选细菌产生明显损伤作用。FTIR分析显示,Sr2+与辐照对Strain No.4菌体有一定协同损伤作用,且处于对数生长期的菌体比迟滞生长期更易受辐射损伤。这种损伤主要表现为菌体蛋白质酰胺基团和多糖中糖环、蛋白质分子中甲基等基团对应谱峰变化。

One strain bacterium was isolated from purple soil of Sichuan basin. It was subject to Bacillus according to analysis re- suits of 16S rDNA. The effect of its biosorption to Sr^2＋under T-ray radiation was studied in this paper. As for the whole kinetic biosorption curves, the results show that bacterial growth rates of test groups have retardation phenomena compared to the con- trol groups without radiation. Such as the appearance of biosorption equilibrium retarded 1.5 d while the max growth rate retard- ed 0. 5 d after the radiation. SEM analysis showed that the bacterial cells had abnorrnity distortion after radiatior; This proved that γ-ray radiation can bring obvious damage to experimental bacterial cells. FTIR analysis results indicated that bacteria cells were damaged by radiation and Sr^2＋ has cooperation damage effects with radiation in aqueous condition, and the bacterial ceils of log phase are easier to be damaged by coming forth radiation than those of lag phase. This radiation damage under different radi- ation condition mainly leads to that the characteristic peaks of amylase, protein amide and lipids on bacterial cells are slightly shifted.