0000000000181695
AUTHOR
Gabriele Pastorella
Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode
Abstract Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at graphite electrodes were investigated in potentiostat-controlled electrochemical cells poised at oxidative potentials (0.2 V vs. Ag/AgCl). Chronoamperometry (CA) showed a repeatable biofilm growth of S. loihica PV-4 on graphite electrode. CA, cyclic voltammetry (CV) and its first derivative shows that both direct electron transfer (DET) mediated electron transfer (MET) mechanism contributes to the overall anodic (oxidation) current. The maximum anodic current density recorded on graphite was 90 μA cm − 2 . Fluorescence emission spectra shows increased concentration of quinone derivatives and riboflavi…
Microbial Cells and Biosensing: A Dual Approach - Exploiting Antibodies and Microbial Cells as Analytical/Power Systems
The primary focus of this review is the discussion of how biosensor-based platforms can be used in conjunction with microbial cells for monitoring, environmental and industrial applications. Two approaches will be comprehensively discussed. The first of these will examine how immunosensors can be used for the sensitive and selective detection of bacterial pathogens in a range of diverse and complex sample matrices. Secondly, we discuss the implementation of free and immobilised microbial cells for facilitating the analysis of chemicals and metabolites in cost-effective devices that, in turn, are directly applicable to environmental monitoring. Further examples, relating to the uses and adva…
Zinc oxide and indium tin oxide thin films for the growth and characterization ofShewanella loihicaPV-4 electroactive biofilms
Transition metal oxides (TMO) electrodes provide a suitable platform for spectroscopy- and microscopy-based investigation of viable electroactive biofilms (EABs). Commercially available TMOs, such as indium titanium oxide (ITO), are produced from rare and expensive elements. Thus, there is a significant need to explore alternative technology to meet the demand. ZnO-based TMOs are low-cost and have excellent electrochemical properties. In this study, we report for the first time a model EAB of Shewanella loihica PV-4 on ZnO films deposited on perspex substrates via pulsed laser deposition (PLD). Commercially available ITO electrodes were also used for comparison. 480 Virulence Volume 2 Issue…
Abatement of AO7 in a divided microbial fuel cells by sequential cathodic and anodic treatment powered by different microorganisms
Abstract Microbial fuel cells (MFCs) can allow the treatment of organic pollutants resistant to conventional biological processes by electro-Fenton (EF) process performed in the cathodic compartment. However, EF usually results in a partial mineralization of pollutants. Here, we have studied the possible treatment of such organics in a MFC by a sequential cathodic and anodic treatment. In particular, the treatment of an aqueous solution of Acid Orange (AO7), a largely used azoic dye resistant to conventional biological processes, was performed in the cathodic compartment of a divided MFC by EF. The process allowed the total removal of the color and the partial removal of the TOC, due mainly…
Biofilms: Applications in Bioremediation
Bioremediation uses microorganisms to remove, detoxify, or immobilize pollutants, and does not require addition of harmful chemicals. Bioremediation is particularly suitable for large areas where contaminant concentrations are relatively low and the hydrology of the soil does not support an aggressive chemical remediation strategy. In the last few years, researchers have described the mechanisms of bioremediation for numerous priority pollutants, including chlorinated hydrocarbons, polyaromatic hydrocarbons, and heavy metals. However, most studies published to date have dealt with planktonic cultures grown under controlled laboratory conditions. Microorganisms in the environment occur mostl…
Genetic methods to improve Cr(VI) bioremediation in groundwater
Cr(VI) contamination of groundwater and soils is a primary public health. Bioremediation is an environmental-friendly alternative for Cr(VI) removal from groundwater and soils, but Cr(VI) toxicity limits the efficiency of the process. We use the genome shuffling technique in order to improve Cr(VI) tolerance and Cr(VI) reduction capability of the strict anaerobic bacterium Geobacter metallireducens. We will investigate the mechanism of Cr(VI) reduction in the resulting G. metallireducens mutants through an innovative electrochemical approach. Finally, we will test the best performing mutants in a bench-scale Cr(VI) bioremediation process.
GEOBACTER METALLIREDUCENS MUTANTS FOR CHROMIUM BIOREMEDIATION
Genetic technology to improve biofilms electroactivity for bioremediation applications