Electrochemical Characterizations of four Main Redox–metabolites of Pseudomonas Aeruginosa

Abstract

Bacterial identification is of first importance in clinic nowadays. For few years, electrochemistry appears as a reliable route for characterizations outside of laboratories. Nowadays, researchers mainly focus on the opportunistic pathogen Pseudomonas aeruginosa because of its production of the Pyocyanin toxin which has an electrochemical case study behavior. Other P. aeruginosa secreted molecules are also studied in a lesser extent. This work deals with the systematic electrochemical characterizations in aprotic and protic solvents of 4 main metabolites of this bacterium in the view of multispecies detection of P. aeruginosa. We report here the behavior of the 2‐Heptyl‐4(1H)‐quinolone (HHQ), Pseudomonas Quinolone Signal (PQS), Pyocyanin (PYO) and the 2′aminoacetophenone (2‐AA). All the mentioned species are clearly visible by using electrochemical techniques (cyclic and square wave voltammetries). The 2 most suitable species for electrochemical detection appear to be PQS and PYO because of their detection at low potential.

Optimized Production of a Redox Metabolite (pyocyanin) by Pseudomonas aeruginosa NEJ01R Using a Maize By-Product

“…Hence, the ratio i pa /i pc at different scan rates was evaluated ( Figure 5 d). The behavior confirmed that the reversal oxidation process I a was controlled by diffusion, with adsorption of PYO significantly reduced over the electrode surface [ 10 , 47 ]. Finally, considering low scan rates, where the adsorption process was not presented, a value of |Δ E p | = 0.035 V was calculated, which indicated a two-electron transfer, according to Equation (6).…”

“…The redox process for PYO was studied through cyclic and square wave voltammetries. PYO and other redox metabolites included in the secretome of P. aeruginosa could be used as electrochemical biomarkers to detect its presence in a bacterial culture supernatant [ 10 ]. Furthermore, P. aeruginosa is considered an electrogenic microorganism and is used in bioelectrochemical systems for electrical energy production, carried out by direct electron transfer (through cytochromes in outer membrane or bacteria pili) and indirect electron transfer (through secondary metabolites excreted by bacteria).…”

Biological and clinical significance of quorum sensing alkylquinolones: current analytical and bioanalytical methods for their quantification

“…This strategy has been reported in many occasions for the detection of PYO [128,129], one of the main virulence factors regulated by the QS, which shows well-known redox properties. However, the electrochemical behaviour of AQs has been only partially known until very recently [130]. Thus, HHQ shows only one purely irreversible oxidation wave at high potential around + 0.99 V over the first CV scan when using glassy carbon (GC) working electrodes (1 mm diameter) and Ag/Ag + reference electrodes in organic media.…”

Detection of Quorum-Sensing Molecules for Pathogenic Molecules Using Cell-Based and Cell-Free Biosensors

“…Gram-negative bacteria use HSLs as signaling molecules to regulate gene expression in a concentration-dependent manner. However, some strains produce additional non-homoserine lactone molecules, such as the PQS in P. aeruginosa [31,32]. Most Gram-negative systems contain a LuxI/LuxR QS network homolog.…”

“…PQS has an oxidation and reduction peak at +0.233 V and +0.178 V, respectively. Pyocyanin can be detected via electrochemically with symmetrical peaks at −0.16 V and an irreversible oxidation peak at +0.8 V [32].…”