Production of selenium nanoparticles in Pseudomonas putida KT2440.
Production of selenium nanoparticles in Pseudomonas putida KT2440.
复制标题
Pseudomonas Putida KT2440中的硒纳米颗粒的产生。
DOI：
10.1038/srep37155
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发表时间：
2016-11-15
影响因子：
4.6
通讯作者：
Chavarría M
中科院分区：
文献类型：
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作者：
Avendaño R;Chaves N;Fuentes P;Sánchez E;Jiménez JI;Chavarría M
硒 (Se) 是细胞的必需元素，在医学和技术领域有多种应用；微生物在环境中的硒转化中发挥着重要作用。在这里，我们报告了土壤细菌恶臭假单胞菌 KT2440 从亚硒酸盐合成元素硒纳米颗粒（纳米 Se）的先前未鉴定的能力。我们的结果表明，恶臭假单胞菌能够在有氧条件下将亚硒酸盐还原为纳米硒，但不能将硒酸盐还原为纳米硒。动力学分析表明，在添加亚硒酸盐（1 mM）的LB培养基中，从中间指数阶段开始以0.444mmol L−1 h−1的速率还原为纳米硒，最终转化率为89%。透射电子显微镜 (TEM) 测量表明，恶臭假单胞菌合成的纳米硒颗粒的尺寸范围为 100 至 500 nm，并且它们位于周围介质中或与细胞膜结合。涉及动态光散射 (DLS) 的实验表明，在水溶液中，回收的纳米 Se 颗粒的尺寸范围为 70 至 360 nm。恶臭假单胞菌的快速转化动力学、纳米硒的容易回收和代谢多功能性为使用这种模型生物作为生产硒纳米颗粒的微生物工厂提供了机会。
Selenium (Se) is an essential element for the cell that has multiple applications in medicine and technology; microorganisms play an important role in Se transformations in the environment. Here we report the previously unidentified ability of the soil bacterium Pseudomonas putida KT2440 to synthesize nanoparticles of elemental selenium (nano-Se) from selenite. Our results show that P. putida is able to reduce selenite aerobically, but not selenate, to nano-Se. Kinetic analysis indicates that, in LB medium supplemented with selenite (1 mM), reduction to nano-Se occurs at a rate of 0.444 mmol L−1 h−1 beginning in the middle-exponential phase and with a final conversion yield of 89%. Measurements with a transmission electron microscope (TEM) show that nano-Se particles synthesized by P. putida have a size range of 100 to 500 nm and that they are located in the surrounding medium or bound to the cell membrane. Experiments involving dynamic light scattering (DLS) show that, in aqueous solution, recovered nano-Se particles have a size range of 70 to 360 nm. The rapid kinetics of conversion, easy retrieval of nano-Se and the metabolic versatility of P. putida offer the opportunity to use this model organism as a microbial factory for production of selenium nanoparticles.