Immobilization of Shewanella oneidensis MR-1 in diffusive gradients in thin films for determining metal bioavailability. (November 2015)

• Record Type: Journal Article
• Authors: Baker, Paul W.; Högstrand, Christer; Lead, Jamie; Pickup, Roger W.; Zhang, Hao
• Is Part Of: Chemosphere. Volume 138(2015)
• Page Start: 309
• Page End: 315
• Publication Date: 2015-11
• Subjects: Diffusive gradient thin films (DGT) -- Biological mobilizing DGT -- Shewanella oneidensis -- BacLight; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2015.06.018
• Languages: English
• ISSNs: 0045-6535

Abstract

Graphical abstract: Highlights: Live bacteria were incorporated into BMDGTs. BMDGTs showed some effects on mobilization of metals. BMDGTs did not show increased iron mobilization by Shewanella oneidensis . Abstract: Assessing metal bioavailability in soil is important in modeling the effects of metal toxicity on the surrounding ecosystem. Current methods based on diffusive gradient thin films (DGTs) and Gel-Integrated Microelectrode are limited in their availability and sensitivity. To address this, Shewanella oneidensis, an anaerobic iron reducing bacterium, was incorporated into a thin layer of agarose to replace the polyacrylamide gel that is normally present in DGT to form biologically mobilizing DGT (BMDGT). Viability analysis revealed that 16–35% of the cells remained viable within the BMDGTs depending on the culturing conditions over a 20 h period with/without metals. Deployment of BMDGTs in standardized metal solutions showed significant differences to cell-free BMDGTs when cells grown in Luria Broth (LB) were incorporated into BMDGTs and deployed under anaerobic conditions. Deployment of these BMDGTs in hematite revealed no significant differences between BMDGTs and BMDGTs containing heat killed cells. Whether heat killed cells retain the ability to affect bioavailability is uncertain. This is the first study to investigate how a microorganism that was incorporated into a DGT device such as the metal reducing bacteria, S. oneidensis, may affect the mobility of metals.