Silica-immobilization of Geobacter sulfurreducens for constructing ready-to-use artificial bioelectrodes

Estévez-Canales, M. and Pinto, D and Coradin, T and Laberty-Rober, , C. and Esteve-Núñez, A. (2018) Silica-immobilization of Geobacter sulfurreducens for constructing ready-to-use artificial bioelectrodes. Microbial Biotechnology, 11 (1). pp. 39-49. ISSN 17517915

This is the latest version of this item.

Full text not available from this repository. (Request a copy)
Official URL: http://dx.doi.org/10.1111/1751-7915.12561

Abstract

Microbial electrochemical technologies (METs) rely on the control of interactions between microorganisms and electronic devices, enabling to transform chemical energy into electricity. We report a new approach to construct ready‐to‐use artificial bioelectrodes by immobilizing Geobacter sulfurreducens cells in composite materials associating silica gel and carbon felt fibres. Viability test confirmed that the majority of bacteria (ca. 70 ± 5%) survived the encapsulation process in silica and that cell density did not increase in 96 h. The double entrapment within the silica–carbon composite prevented bacterial release from the electrode but allowed a suitable mass transport (ca. 5 min after electron donor pulse), making the electrochemical characterization of the system possible. The artificial bioelectrodes were evaluated in three‐electrode reactors and the maximum current displayed was ca. 220 and 150 μA cm−3 using acetate and lactate as electron donors respectively. Cyclic voltammetry of acetate‐fed bioelectrodes revealed a sigmoidal catalytic oxidation wave, typical of more advanced‐stage biofilms. The presence of G. sulfurreducens within composites was ascertained by SEM analysis, suggesting that only part of the bacterial population was in direct contact with the carbon fibres. Preliminary analyses of the transcriptomic response of immobilized G. sulfurreducens enlightened that encapsulation mainly induces an osmotic stress to the cells. Therefore, ready‐to‐use artificial bioelectrodes represent a versatile time‐ and cost‐saving strategy for microbial electrochemical systems.

Item Type: Article
Subjects: Q Science > QD Chemistry
Q Science > QR Microbiology
Depositing User: Belén Barroeta
Date Deposited: 03 Apr 2018 09:05
Last Modified: 03 Apr 2018 09:05
URI: http://eprints.imdea-agua.org:13000/id/eprint/892

Available Versions of this Item

Actions (login required)

View Item View Item