Iron Uptake Kinetics and Magnetosome Formation by Magnetospirillum gryphiswaldense as a Function of pH, Temperature and Dissolved Iron Availability
Iron Uptake Kinetics and Magnetosome Formation by Magnetospirillum gryphiswaldense as a Function of pH, Temperature and Dissolved Iron Availability
复制标题
DOI：
10.1080/01490451.2011.594146
复制
发表时间：
2011-08
影响因子：
2.3
通讯作者：
C. Moisescu;S. Bonneville;Sarah S. Staniland;I. Ardelean;L. Benning
中科院分区：
文献类型：
--
作者：
C. Moisescu;S. Bonneville;Sarah S. Staniland;I. Ardelean;L. Benning
为了评价趋磁性细菌(MTB)在铁的生物地球化学循环中的作用，在较宽的pH、温度和铁有效性范围内，研究了趋磁性细菌(MTB)对铁的摄取和磁小体形成的动力学。除pH值为5.0外，所有培养物均显示出显著的细菌生长。在最佳条件下(即pH 7和28℃)，对溶解Fe(III)的吸收速率可用Michaelis-Menten型动力学模型描述，其最大吸铁速率Vmax为11×10−12μ摩尔细胞−1h−1，亲和常数Ks为26μM Fe。在不同pH值下合成的磁小体的高分辨率成像显示了大范围的形貌和大小，说明了环境条件对MTB形成磁铁矿晶体的影响。
The dynamics of iron uptake and magnetosome formation by the magnetotactic bacteria (MTB) Magnetospirillum gryphiswaldense was investigated at a broad range of pH, temperature and iron availability to evaluate the role of MTB in the iron biogeochemical cycle. Except at pH 5.0, all incubations have shown significant bacterial growth. However, magnetosome formation was limited at pH 8.0 and 9.0 as well as at 4°C, 10°C and 35°C. At optimal conditions (i.e., pH 7 and 28°C), the uptake rates of dissolved Fe(III) as a function of initial Fe concentration can be described by a Michaelis-Menten-type kinetic model with a maximum iron uptake rate, Vmax ,, of 11 × 10−12 μmoles cell−1 h−1 and an affinity constant, Ks of 26 μM Fe. High resolution imaging of magnetosomes synthesized at the different pH values, revealed a large range of morphologies and sizes, which illustrate the impact of environmental conditions on the formation of magnetite crystals by MTB.