PRODUCTION AND CHARACTERIZATION OF ELECTROGENIC PIGMENTS BY FILAMENTAL FUNGI ISOLATED FROM
CAATINGA BIOME AND APPLICATION AS ELECTROCHEMICAL MEDIATOR.
Microbial fuel cell, fungal pigments, electrochemical mediator,
bikaverina.
The microbial fuel cell (MCC) is a device that generates electrical energy from biochemical processes using microorganisms or enzymes. These devices feature a cathodic and an anodic compartment and prove to be an environmentally friendly and viable alternative for the generation of cleaner energy. Electrochemical mediators are substances that have the ability to be reduced and oxidized (redox system) in order to serve as a transport medium for electrons. In CCM, the redox capacity of the mediators helps to achieve greater electron transfer in cathodic or anodic agents, thus optimizing the energy generation process. Several synthetic mediators have been studied and used, but many are toxic, not being recommended for a more ecological energy source. In this context, pigments of fungal origin demonstrate redox capacity, being considered candidates for use as electrochemical mediators. Furthermore, it is hypothesized that the pigments can act as "molecular wibe" bridges to couple the charge transfer within the biofilm to the extracellular charge collecting electrode to produce energy. In this work, the production of pigments by fungi isolated from soils of the Caatinga biome was initially carried out and they were evaluated in terms of their redox properties as electrochemical mediators in a CCM, from the production of red pigments from Aspergillus sp. UCP1349 and green from Penicillium sp. CPU1152. The analyzes were carried out through cyclovoltametry of the pigments with KCl and H3PO4 solutions, as support analytes, with a scanning potential of -1.0V to 1.0V, speed of 0.1Vs-1 in a system composed of three electrodes: glassy carbon working electrode; against platinum wire electrode; reference electrode Ag/AgCl (KCl). The analysis results showed that the pigments present redox pairs for application as electrochemical mediators. Then, pigments were introduced into a 200ml cathode at three different concentrations (1mg/L, 2mg/L and 5mg/L) of CCM containing the commercial enzyme Trametes versicolor laccase at 200 U/L-1. The 100ml anode was filled with 20mM potassium ferrocyanide. The results obtained suggest that the very active enzymes and the isolated pigments of the studied fungi generate the future possibility of a coupled system of two or more electroactive microorganisms. Studies are being conducted with the bikaverin pigment isolated from Fusarium oxysporum UCP 1624, with the objective of demonstrating the electroactive capacity in electron transport as an electrochemical mediator for application in a CCM. Innovative investigations will be conducted with biosurfactants to demonstrate the ability to transport electrons as an electrochemical mediator, and an anodic or cathodic chamber with potential for bioremediation by the biosurfactant can also be generated while simultaneously acting on the interior system to generate energy in a CCM and the results obtained will be
to generate a Patent.