Wang Fei, Yao Jun, Chen Huilun, Yi Zhengji, Yu Chan, Tuo Yujie, Ma Lan, Yu Qian
School of Civil and Environmental Engineering and National International Cooperation Based on Environment and Energy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing, 100083, People's Republic of China.
Environ Sci Pollut Res Int. 2014;21(15):9278-86. doi: 10.1007/s11356-014-2884-x. Epub 2014 Apr 12.
A 2-(n-morpholino)ethane sulfonic acid (MES)-buffered minimal medium with low levels of metal chelates was used to evaluate the heavy metal (Co+2, Pb+2, Zn+2, Fe+2, Fe+3, Cd+2, Cu+2, and Cr+6) toxicity to Pseudomonas fluorescens through minimizing the limitation of the existing medium. The interaction between bacteria and heavy metals was real-time monitored by microcalorimetry and reflected by thermogenic curves. Compared with the main parameters, microbial growth rate constant k and total heat evolution Q total, a general order of toxicity was found to be Fe+3<Co+2<Fe+2<Cu+2<Cr+6<Zn+2<Pb+2<Cd+2. The main metal speciation was Co+2, Zn+2, Fe+2, Cd+2, PbOH+, Fe(OH)+2, CuOH+, HCrO4-, and CrO4(-2) at pH 6.4. These metal speciations are main factors to exhibit the metal toxicity to bacteria. To validate their interaction, the surface chemical functional groups of P. fluorescens biomass identified by Fourier transform infrared (FTIR) were amino, carboxyl, hydroxyl, and phosphoryl groups, which maybe involved in the biosorption of metal ions.
使用含有低水平金属螯合物的2-(N-吗啉代)乙磺酸(MES)缓冲基本培养基，通过最小化现有培养基的限制来评估重金属(Co²⁺、Pb²⁺、Zn²⁺、Fe²⁺、Fe³⁺、Cd²⁺、Cu²⁺和Cr⁶⁺)对荧光假单胞菌的毒性。通过微量量热法实时监测细菌与重金属之间的相互作用，并通过产热曲线反映出来。与主要参数微生物生长速率常数k和总产热量Q总相比，发现毒性的一般顺序为Fe³⁺<Co²⁺<Fe²⁺<Cu²⁺<Cr⁶⁺<Zn²⁺<Pb²⁺<Cd²⁺。在pH 6.4时，主要的金属形态为Co²⁺、Zn²⁺、Fe²⁺、Cd²⁺、PbOH⁺、Fe(OH)⁺²、CuOH⁺、HCrO₄⁻和CrO₄²⁻。这些金属形态是表现金属对细菌毒性的主要因素。为了验证它们之间的相互作用，通过傅里叶变换红外光谱(FTIR)鉴定的荧光假单胞菌生物质的表面化学官能团为氨基、羧基、羟基和磷酰基，它们可能参与金属离子的生物吸附。
