Abstract
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.
Highlights
The complexity of natural systems, such as the biosphere, calls for the creation of new paths for research and knowledge development.[1,2] In the past century, the development of systems theory provided a broad basis for the “ecology of practices” in Earth and human sciences.[3,4,5,6] Here, we propose specific practice of model development relevant to biogeochemistry and in a broader sense to transdisciplinary investigations
Equilibrium modeling We propose a potentiometric approach to explore the experimental behavior of the complex soil subsystem model, the fungal mycelium biomass, under perturbed conditions
Since the metal ions were obtained from a diluted nitric acid solution, it is possible to observe the presence of nitrate (N–O stretch) at 1050 cm-1 for the [mycelium/metal ion] spectra
Summary
The complexity of natural systems, such as the biosphere, calls for the creation of new paths for research and knowledge development.[1,2] In the past century, the development of systems theory provided a broad basis for the “ecology of practices” in Earth and human sciences.[3,4,5,6] Here, we propose specific practice of model development relevant to biogeochemistry and in a broader sense to transdisciplinary investigations. The components (A, B, C and D) and their respective deprotonation constants suggest the presence of a complex biological matrix composed by the usual fungal biopolymers and biomolecules such as carbohydrates, proteins, nucleic acids and (in)organic salts as observed in the Raman scattering measurements (Figure 3 and Table 1).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
