Equilibrium and Out-Of-Equilibrium Investigation of Proton Exchange and CuII and ZnII Complexation on Fungal Mycelium (Trametes hirsuta)

• Autor(a) principal: Almeida,Vicente R.
• Data de Publicação: 2016
• Outros Autores: Szpoganicz,Bruno, Chou,Lei, Baert,Kitty, Hubin,Annick, Bonneville,Steeve
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532016000100015
• topic: potentiometry; out-of-equilibrium thermodynamics; mycelium/metal ion complexes; intermediate technology

This work presents potentiometric investigations of [mycelium/metal ion/water] complex systems and the development of a new model investigating the ion-mycelium-fluid interactions. Since pH is a major parameter in soil ecology exhibiting large fluctuations, we proposed an improved equilibrium and also out-of-equilibrium potentiometric titration method in order to characterize the proton exchange behavior of the [mycelium/metal ion/water] system. Our model describes the dynamic relations and interactions within the soil complex subsystems consisting of fungal mycelium of Trametes hirsuta, water with or without metal ions (CuII and ZnII). Equilibrium modeling based on potentiometric titrations can be well described using four mycelium related components which are active in the pH range studied. In addition, our equilibrium calculations show clear differences with respect to metal-mycelium interactions: CuII interacts with acidic and basic deprotonable sites, while ZnII binds with neutral and basic deprotonable sites. Potentiometric out-of-equilibrium (i.e., perturbed pH) characterization suggests that important fungal heterogeneous complexity may act as definite proton pressure entities under continuously perturbed soil conditions. Raman micro-spectroscopy was also used to characterize the [mycelium/metal ion/water] complex systems. Our results demonstrate that potentiometry is a useful tool (intermediate technology) in studying biological complex matrices, facing pH perturbations, as well as their interactions with metal ions.