Related Experiment Video
Updated: Feb 14, 2026

Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion
Published on: January 30, 2018
Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion
Pao-Hung Lin1, Ying-Tang Huang2, Fu-Wen Lin3
1Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology; plin21@mail.ntust.edu.tw.
Abstract:
We present a method, the bacterial mineral excretion (BME), for synthesizing two kinds of microcapsules, sodium tungstate and sodium molybdate, and the two metal oxides' corresponding nanoparticles-the former being as small as 22 nm and the latter 15 nm. We fed two strains of bacteria, Shewanella algae and Pandoraea sp., with various concentrations of tungstate or molybdate ions. The concentrations of tungstate and molybdate were adjusted to make microcapsules of different length-to-diameter ratios. We found that the higher the concentration the smaller the nanoparticles were. The nanoparticles came in with three length-to-diameter ratios: 10:1, 3:1 and 1:1, which were achieved by feeding the bacteria respectively with a low concentration, a medium concentration, and a high concentration. The images of the hollow microcapsules were taken via the scanning electron microsphere (SEM). Their crystal structures were verified by X-ray diffraction (XRD)-the crystal structure of molybdate microcapsules is Na2MoO4 and that of tungstate microcapsules is Na2WO4 with Na2W2O7. These syntheses all were accomplished under a near ambient condition.
Related Concept Videos
Regulation of Sodium and Potassium
Sodium Regulation
Sodium ions make up approximately 90% of extracellular cations, with a normal blood plasma concentration of 136–148 mEq/L. A decrease in blood volume and pressure triggers the release of renin from granular cells in the juxtaglomerular complex (JGC), primarily...
Roles of Electrolytes: Sodium and Potassium
Antiepileptic Drugs: Sodium Channel Blockers
Sodium channel blockers modulate ion channels, particularly voltage-gated sodium channels. They block only sodium ion movement.
Among the most commonly prescribed antiepileptic drugs are...
Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
When dissolved in liquid ammonia, an alkali metal, such as sodium,...
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Water and Mineral Acquisition

